I have most of the stock CFS2 planes changed over to FS2004...well, not really the STOCK STOCK, but the overhauled models by The B-24 Guy. Really need to finish them up and get them uploaded. I have found that K. Malinowski's CFS2 P-47, P-40s, Ju-88s, Ju-188, Ki-100 KO and Otsu, PZL P-37 A and B, and his Raiden work just fine in FS2004...just needs a bit to tweaking in the config file to get them to list in the aircraft selection window properly, and lights and such. The vast majority of Bismarck13's CFS2 planes will work in FS2004...those that won't he has made FS2004 versions of.
Basically, any planes made with Gmax and FSDS2.X and higher stand a good chance of porting over to FS2004.
OBIO