I picked up an inexpensive PB4Y version in 1/72nd scale of the B-24 that was used by both US and RAF Coastal Command to hunt U-boats. The kit (Minicraft) comes with US markings, but I'd rather do a Coastal Command version. For that I need both:

1.) camo guide (colors and manufacturers) and
2.) decals

I haven't found any commercial releases for this aircraft, so I guess I'll need to mix & match with generic roundels, etc. Suggestions?

You should be looking for RAF B-24's rather than PB4Y's, even the PB4Y-1 was somewhat different from the Coastal Command B-24's (which were RAF-modified B-24's rather than the USN-modified ones that the PB4Y-1 is).

CanMilAir's got some Coastal Command B-24 decals oriented towards Canadian units or crews

http://www.canmilair.com/products.asp?cat=61

Thanks, Adam. Xtradecal also has a set (72079) that isn't Liberators but is Coastal Command and looks like the illustrations I've seen. Anyone familiar with that? It's earlier (1942 and before) and is other craft.