Its a real can of worms trying to nail down subtypes, many refs will simply say "IXs" or "Vs" and not say if they were LF Vs or F IXs or LF IXs. It can be a real pain, and it leads to erroneous info.
I only have to point to the B C E wing threads to show how jumbled it can get...then the F and LF stuff on top of that. Freaking alphabet soup. As it is you have to start tracking down serial #s sometimes to figure it out.
If I was in charge in 1942 it would have been like this:
Spit V-5
Spit V-10
Spit IX-5
Spit IX-15
Like that. Done. Violaters would have been shot as examples.
