The Saab J-21 and Curtiss(?) XP-54 have very close layouts. I haven’t taken a close enough look in the past, so can anyone tell me what the major external differences are? I really don’t know much of anything about these two…
Do a search on the net on the the designs and you’ll get plenty of references and see the differences.
The Saab J-21 has a central fuselage, a pusher prop, and a twin boom tailplane arrangement (like a P-38).
The Vultee XP-54 had a very similar layout but had a anhedral/dihedral wing like the Corsair.
The XP-54 was longer, i think, and had a rather slender bullet shaped main pod - and the Saab was a but fatter.
There’s lots of pics on the web - do a Google search - you’ll find everything you need.
Cheers, mate!