I read on the CS Finescale modeler forum that the story behind this white/ red proppeler is quite interesting. Here is what the contributor, named eagle 334 wrote:
"P-51B-7-NA Mustang (43-6913; VF - T): A Markings Chronology"
Here's my time line of Shangri-La's markings, based on the best evidence I can find. All the good, clear, no-mistaking-it photos I've ever seen of Shangri-La show her paintwork and markings in one of three configurations only: (A) Red/White nose with 21-kills; (B) Full-red nose with 21-kills; and finally, (C) The photos taken just before, and then after the April 13th mission as 6913 sat in the Tetlow field, and later next to one of the Heavy Maintenance Service Squadron's "blister" hangars. The latter (C) photos all show a full-red nose with 30 crosses (final score).
Mar 15............. 4th FG receives red noses. The red was painted right over the white ETO recognition nose paint in a hurry with little preparation of the surface prior to application of the red. The very first batch of red paint was purchased from local civilian stores and was a lacquer type with a relatively low pigment content, rather than an enamel; that is, it had almost a nail polish transparent quality - and took 3 or 4 coats to cover well. Very thin and watery as one hangar technician stated. Shortly thereafter, on one of the first flights (March 17?) with the new red noses, some of the Mustangs flew through "rough weather". A sleet storm was encountered by some of the P-51s, and the ice just peeled that cheap red paint right off their spinners. That was why Shangri-La's spinner sported that very ragged edge to the spinners red/white demarcation line. The rear half of the spinner was touched up with red paint, but evidence of the chipping remained just forward of the spinner break (see photo at the bottom of this page). Within a short time, Don had the white forward half of the spinner touched up so that there was a nice hard edge between the red and white parts at the spinner break, making his kite look better and also facilitating better aerial recognition between Don and Johnny in combat. The red/white cowl checkerboard and the red wheels would have been painted on at this time. The nose colors were new at this time in 8AF, and Don wasn't "called" on this unique red/white nose coloration - until later.
Mar 16-18.........VF-T flown with red, then red/wht nose, and 13 crosses on the scroll.
Mar 18..............Kill #14 scored, applied to VF-T several days afterward. 6913 "downed" for maintenance after Don was hit today in the engine.
Mar 20 - 29.........VF-N (43-6572) flown by Gentile in place of VF-T; "N" was parked close to VF-T in photos, so that makes sense. His score goes up to 21 during this time. All white ETO theatre recognition tail bands painted out circa March 23 - in the hangar while maintenance and repair was going on.
Mar 30..............Don "slow times" VF-T after maintenance. Since this is the day after 19, 20, and 21 were scored, I would say that still only 18 crosses would be on the scroll today.
Mar 31..............Another slow time flight for the engine. Right before or right after the test flight, the March 29 kills (19, 20, and 21) were applied to the scoreboard after confirmation came through. Still showing the red/white nose. After the flight VF-T was sent back to 336's hangar for Don's write-ups - still some bugs in the engine.
Apr 1-3.............Gentile was flying VF-N 6572 April 1 when he got no. 22. VF-T was in the 336 hangar these three days to take care of Don's "write ups" from the March 30 and 31 test flights. During this stay in the hangar, VF-T's nose was given her second application of a "full red" nose.
Apr 4-13 ..........Another maintenance test flight for VF-T on April 4. Famous series of photos of Don buzzing up the North runway taken today, which are often misidentified as shots taken right before her crash on April 13. One only has to look at the scroll to see there's no way the "buzz" pictures were taken on April 13th. As of the 4th, 6913 is still showing 21 kills, but now displays its new full red nose. On April 5, Gentile flew VF-N again, so it appears 6913 wasn't yet cleared for combat missions. Don claimed 5 more victories on April 5, bringing him up to 27 total. As of the April 5th mission I think they had just received official confirmation of kill no. 22, possibly on April 4, but they haven't put it on 6913 yet. After the April 5 mission they now have 5 more kills to add to the scroll - after official confirmation for those comes through. Instead of just putting on kill no. 22 first, it was decided to enlarge the victory scroll to a full banner of two rows - to accommodate no. 22 and (shortly) 23-27. I have photos of a painter (Sgt. Fred Rice?) adding white paint to the banner to enlarge it to the full two rows. There are 21 kills showing on the scroll in these photos, so we know no. 22 wasn't put on before the scroll was expanded. The April 13 (crash) photos clearly show a lighter area where new white paint was used to enlarge the scroll. I think that they went ahead and painted on nos. 22-27 the evening of April 7 - - in time for her next scheduled mission the following day. Also, during this time period VF-T's full red spinner peeled [2nd time] probably due to weather, then repainted full red [3rd time]. A photo in the Wolfert book shows Don and Johnny walking away from VF-T with a peeled full red spinner - but not as bad as after the March 17 flight. The Apr 13 crash photos show a beautiful "full red" nose with no peeling.
As for the rest of 6913's markings chronology: We know the nose was repainted overall red during the April 1-3 hangar period (to match the rest of the groups noses) with only 21 kills showing on the scoreboard, i.e., before the scroll was expanded to a full two row banner. Don scored his last 3 kills on April 8, and those last 3 were added to the scroll before the April 13 (crash) mission, for a total of 30 crosses displayed on 6913 at the time of the crash. On my site, on the "Raphael Collection" photo pages, I show the only known photo of Shangri-La before the crash, with 30 crosses displayed. This photo was obviously taken between April 9th and 13th - maybe on the morning of April 13th before the mission, but there's no way to know for certain. Notice the "mismatched" engine panel Olive Drab/Neutral Gray paint demarcation line in this photo, which was obviously the result of using a "replacement" panel.
You are right, sometimes it is realy hard to keep the shading on the surfaces in harmony. That is why I like your shading on the 1/32 P-39. 
) but in the photos below , I'll show you how I place the decals & some already placed. In the photos there are not completely dried, that's why you can see the film 
) never seems to end.
