The basic facts are clear. Gary's pics matching my overview.
I started wondering when I learned that Dragon's A3 (#3546) has no option for the early M1 Cupola - w/o bulged hatch cover and G305 Riser. Ok, it's Dragon. The none-bulged hatch cover needed for the early cupola is included in the Magach 1/2 kit only so far - an A2/A2C likely to come in future. However.
Back to A3 Mod B.
According to Hunnicut, page 230
"The vision block ring [G305] and other late modifications were eventually retrofitted to the earlier M48A3s. After that program was complete, the Mod B designation was dropped."
A3 conversion started in 1962, A3 Mod.B 1967.
Does '...other late modifications...' means ALL of them? headlights, fenders,... and engine rear door with rear light housing?
Or just selected ones? making Dragon A3 an early A3 retroffited with parts of Mod B programm, or is it fantasy?
USMC M48s differs again.
That was my starting point.
The question what happend to M48 given away before converted in US when upgraded by the new user-Nation, differs from Nation to Nation, and specially with IDF.
Indeed I wondered if IDF changed the rear door when started dieselasation of Magach 2, as Mark pointed out.
So, thanks for all the responses and pics so far! I'll carry on sampling...