I think they missed the boat on the M48.
From the Patton-Mania website:
"The first production M48s can easily be distinguished by the .50cal being mounted on an external cradle without any armor protection.
The M48A1 received the M1 commanders’ cupola providing armored cover and enclosing the .50 cal."
Also, most M48s had smaller loaders’ and driver’s hatches. They were later enlarged on the A1 and carried through later versions.
Basically, it looks like their M48 is actually an early M48A1. Looking at sprue shots from the I 
Kit website, the M48 looks to have one extra sprue which has the tensioner wheels and mounts, a different turret basket, an external radio box, and a muffler for an APU.
This website explains the M48 well:
http://afvdb.50megs.com/usa/pics/m48patton/m48patton.html#TOP
And the M48A1:
http://afvdb.50megs.com/usa/pics/m48patton/m48patton.html#M48A1
To backdate it to an M48, you need a Chrysler cupola for the TC’s position. It looks similar to an Urdan cupola, but is different.
Micro Cosmos out of Greece makes the Chrysler cupola.
