I've noticed in pictures from Berlin 1945 that some IS 2 have track with teeth every link and some a tooth every other link , could these track link types work together ? Really easy to see on the nose mounted spare track . Also some have a ammo port on the lower left hull side by the road wheels , some don't .. was this specific to a certain factory or just a case of early hull/ late hull ( the IS SPG types had this ammo port as well ) ? Thanks

The track links without the center guide tooth were split links, and alternated with the solid (toothed) links. They were hinged identically, and the whole track run could be solid links, but this was rare until after the war. As additional links were added, the sequence was sometimes off, with two split links or two solid links side by side.

The ammo loading port on the left side was a late modification. It was not usually seen on the original IS-2 with the stepped nose. It was usually present on vehicles with the straightened glacis and fixed driver's periscope.

Thanks for the information . Just picked up an Italeri 1/56 scale IS 2 and wanted to add a few bits and pieces to make it more model and less war gamey