Originally Posted by
longer ron
As JTC posted above the T1A conversion was also a 'Roll Up' modification update programme which included stuff completely unrelated to the AIM 9 conversions (Rear Wing Mountings on the fuselage at Frame 29 were a fun job LOL)
I'm stretching memory here and by no means authoritative, but wasn't a T.1(W) a T.1 original build, subsequently modded for pylons and AIM9, as distinct from a T.1A built to that spec with the additional mods as well.