Finished the build today. Here the second part of the modifications that were done:
Step 7: Omit the part C24 or the old style exhaust wont fit.
Step 8: The rear plate needs to be backdated to hold the old T-72 spare tracks. You have to close all the holes except the ones for towing hooks and barrel holder. You can use part A10 to hold the spare tracks.
I modified the barrel holder as there are no barrels on the original demonstrator tank.
Step 10: Replace the T-90 style tracks with the T-72 tracks. This part is a little bit tricky. You need the T-72 style sprocket wheels. The T-72 tracks wont fit the T-90 sprockets. You can use one from Trumpeter T-72 A/B (except the T-72 Mod 1990) kits or from Tamiya T-72 kit.
Step 11: Part C27 was used instead of C28 as there is no refueling line for the barrels.
Step 12: Fit the old style exhaust. I found one in my spare box from the previous T-72 builds and didnt need to use the one from Miniarm.
1. July at 20:01:27