the jubilee was the 50th year anivers. of ford.. it was during 1953.
The NAA was the tractor model, a few were made late 52, the bulk of them in 53, then some more in 54 .. by the end of 54 the 00 series wqas tooled up.
ths.. 52 and 54 NAA are actually more 'rare' than 53 NAA, which were called a jubilee, and had a different nose medalion.
as for changes from early to leat.. not much.. a flywheel bushing vs bearing, the nose badge, and location of the sn was moved from the engine to the bellhousing aft of the starter.
good 134ci ohv red tiger engine. one of fords best designs IMHO.. very robust. I like them much better than the N flatties.
if ya got specific question, post em.
as for other forums.. there is a antique ford forum here, but less traffic.
Antique Tractors - Yesterday's Tractors : Antique Tractor Headquarters has a very active ford forum.. also sells parts too. I split my time between TBN and ytmag.
both VERY good sites.
soundguy