There's enough build threads out there on this one, so I'm just going to post my mods. If there's interest, I'll continue during the rest of the build.

First off, if you know me, you know there's no way the IR emitter is going to be visible. Fortunately, the IS-2 mantlet has a great sight hole, so no cosmetic changes are necessary. Unfortunately, the elevation pivot design doesn't allow for the normal coax type, the emitter tube had to be connected to the mantlet, but has to pass over the turret with the pivot points on the inside edge, not the outside.