The KV with rounded turret is some fantasy tank that never existed even in projects. It has incorrect armor thickness too.
The new one is historically correct.
OK, then why don't u place a new historical tank and create an appropriate mission for it with a polygon?
There is no need to replace and SPOIL existent tank, just add er personal unit and leave along what already done. I'm not obsessed with history and realism. SF is just a game for me. It's not a guidance to get info as for WWII.
At least, pay attention that somebody spent much efforts to put this tank in the game.
BTW
All my missions (except one) are fantastic. U don't like them, then don't play.