Hanno,
According to "Tanks illustrated no.3, Israeli tanks and combat
vehicles" quote "Some M3's were converted into tank destroyers
by adding the French 90mm DEFA F1 gun. This gun was mounted on
old 6pdr carriages, and the basic carriage was towed behind the
half-track."
What they mean by "the basic carriage" I don't know but there is a
clear photo of the half-track in the book and you can see something
being towed by the half-track and it looks like a gun carriage but
you can't see the weels etc. It doesn't make much sence to me towing
an empty gun carriage behind the half-track unless they can lift
the gun out of the half-track in a simple way, but then why do they
mount the gun in the half-track in the first place??.
The photo was made somewhere in '73-'74 there are M60A1's incl.
cupola in the same page, they got most A1's in '73 out of the
NATO-depot's and later removed the gun-cupola's. The half-track
still has the radiator louvres in the front, so it probably has the
original engine, most diesel-powered half-tracks have an armour-
plate over the louvres.
I probably have some more information on the Israeli half-tracks,
but I firts have to find it in my books.
Greetings Auke.