This 48 scale kit I have had in the stash for a few years, even though the boxart is for the J version, the kit is actually of the older H version, with a new sprue covering the required bits to built the newer J Model.
After cutting the rear fuselage section in 2, {the kit supplies the fuselage as a 4 piece unit}, I now have 6 bits to glue together for the required fuselage extentions. Cutting the floor plate was the easy part as the forward extention section will be hidden {so no need for the floor cargo roller replacements.
Intending to build this with the crew side door open, I added a little scratch building to this area to cover some of the ejection pin marks in the bulkheads.
The fuselage extentions are from styrene sheet od 0.5mm thick laminated as a 3 ply to roughly cover the kit fuselage thickness.

The pix below show the boxart of the kit I have as my model subject, 2 views of the crew entry and the fuselage portside with glued extention parts fitted with the starboard side showing the difference between the old H model fuselage.

This looks promising so far. I'll be following this one with interest.

Whoa, looks like a great start Rob. How did you achieve cutting through it and with straight lines. I too will be very interested in seeing progress and finished photos as this is my (only) favorite plane with props. I like the bulk head so far. How much detail is going into your Herc! Do you have plans on loading up the cargo bay.

I once started doing a 1/48th H' model, kind of lost interest. I do have plans on finishing it someday. I wired up the cargo bay for lighting and my plans are to have a Huey tied downed to the floor.

Keep us posted,
Joe

Joe,

Cutting the rear fuselage section was done by laying masking tape on the panel line and cutting using a razor saw.

The interior detail {with exception of the kit parts at the main wheel well and the roof area over the rear cargo door}, will remain as due to the fuselage extensions the remainder would have to be scratch built.
I have experimented with tissue as a medium to create the fuselage matting and twine for the cargo nets.

Getting RAAF decals for this bird maybe a problem, I know the 'H' decal sheet is available but for the 'J' the decals are the Dark Gull Grey, so I may have to make up something for this.