I'm skint or I'd buy this in a heartbeat, I've a 50s and for me it is the finest .177 gun I've ever shot.
A 35 stock will fit, hole centres are the same as are the mounting points, all you will need is some 30mm ID 2.5 wall alu tube and slit it down the middle to line the 35 stock with, it make a much more manly fitting got too.
Good luck with the sale but I doubt you will need it