Let me show my "Cat", please. As a prototype I choosed the machine that took a part in the Kursk battle. The model sources was:
Photoetched kit from "Armory"
"RB Model" barel
"Eureka XL" cable
The assembly was going easy and I would not like to write too much. I described the assambly process on ScaleModels (http://scalemodels.ru/modules/forum/viewtopic_t_58928_start_0.html) But it is in Russian. And I'm just showing the result here.