I note that the M48 Patton was fitted with T97E2 tracks. Would it be feasible to replace these with the octagonal block tracks if I were modelling an IDF version of the tank? Also, I have read that the 'Urdan'cupola was actually taken from the Sherman tank ... correct? (if so, which version of the Sherman?)

The Urban cupola was a version of the M1 Chrysler cupola. Before the Urdan, some M48s had the Vision cupola installed from the Sharman tank. I don't know anything about the tracks.

What time frame are you thinking of?

The T97 tracks were on all IDF M48's up to the time of the 1973 Yom Kipper war. The new T-142's were introduced in the early 1970's and could be fitted after that time. Given the IDF's habit of using the tracks 'til they were completely worn out, it might be unlikely.

The Urdan (manufactured by Urdan Industries) cupola was locally designed and built and did not come from an M4. Conceptually it bears some similarity to the cupola on the US M1 MBT series (the lid can be horizontal while the hatch is open) but other than that they are completely different.