Your spelling was not that bad, Gip, it is pronounced "Mag'ach".
The Mag'ach still has the 105mm gun used on the M60, if I remember it right. The Merkava has been upgraded with the Rheinmetall 120mm smoothbore meanwhile. The Mag'ach also uses the Merkava all-steel tracks now (which are indeed derived from the Soviet style tracks seen on the T-55/62/72 series you mentioned). The turret of the Mag'ach 7 is made up of a passive Chobham-type laminate armor, unlike the Mag'ach 6 which used the Blazer explosive reactive armor bolted to the standard M60 turret. Like Major Gronovius already mentioned, the AEF Designs set is the only one out there. If you need reference, I have some pictures for you. Mail me and I will mail them to you if you want. Here is a site that has some good info:
http://idfmodelling.free.fr/
HTH
David Miller