Almost. There is a version that has a small MG turret with a 73mm rcls mounted externally on the turret. Here is a description from Wikipedia:
OT-65A “Vydra” (Otter) – OT-65 with a turret of the OT-62B TOPAS. The entry hatches have been moved so now they are positioned behind the turret. It also has additional protection on IR driving lights.
Having just looked at your site, the conversion would be very easy to make. The turret from your OT62A will work, just add the 73mm recoilless, and modify the roof of your OT65 to accommodate the turret, and basically, you have it. I don’t know if it would be profitable given the cost to mold and produce, but at least the mastering cost would be relatively low (I think). I only need three of them (which is why I haven’t made one (time is my enemy)), and am guessing that gamers who have a use would only buy 1-3 models at the most.