I forget the details but I know it was used on the russian front..If I recall the turret couldn't rotate(probably too many issues with the turret-ring set-up)), it belonged to a unit that was famous for piecing together weird combinations like this..a few of the hardcore guys here will probably be able to tell you everything about it...

The Combat history of 653 says it was a 'recovery' Panther with a Pz IV turret bolted in place and not able to rotate.