I am told by Ian Mander that Kostin went to Italy to work for Rossi who insisted on Rossi appearing on the crankcase despite them being cast in the Ukraine (possibly by Yakovlev). I have no idea what transpired but only about 10 engines were made (some sources say only 6). Ian's theory is that to build an engine to Kostin's standard was just too labour intensive; he tells the story of watching Kostin working on an engine using a tobacco tin full of different pieces of wood impregnated with diamond powder. He tells me that as many as nine different radiuses and angles might be put on a piston before it fitted to Kostin's satisfaction