Yes, you could get a distillate fueled CA.. How many were built:;;good question,?
The B,C, and CA tractors are all over fifty years old...Throughout their years, many of these machines have been overhauled more than once...Each time an overhaul in performed, it is not uncommon to install updated components.. Updated piston and sleeve kits have been used for decades... And, not to mention both OEM and aftermarket sources, and overbore kits.. Nowdays, when the head is removed from an old tractor, you can expect to find just about any type of piston.. For me, if I fould some old distillate or 5.7:1 ratio gas pistons in a CE engine, I would not reuse them.. Mater of fact; I doubt that I would reuse ANY 3 3/8" piston,,, I would most likely update to an overbore kit.. That overbore kit will work equally well in all three CE engined tractors, the B,C,and CA..The governors can be tweaked, and the carbs fine tuned.... When updated;
The tractor's former compression ratio and some original specifications ((horsepower for one)) are "history"...for that tractor; anyway.
But, when the service, operators, and parts manuals were published for a tractor, they contained the information which was current at the time of publication. And,, this information would STILL be current for an unaltered tractor, no matter how old..