There are indeed a Mauser 98 action. I spoke with Ralf Martini and he said they could do the ream job no problem.
If you need dies, Wholesale has the RCBS for $37.99
Wood worm, the bolt DOES have to be modified unless you go with a high scope mount.
The 64 Brenneke will not leave enough meat in the barrel according to Ralf Martini as they run at a higher pressure. Also the magazine box has to be stretched a bit to fit the longer Brenneke cartridge.
I was going to do this to my 146 until I found a ZG47.
One advantage to the 146 I had was you could seat the bullet to near the same length as the 9,3x62 and get a bit more powder capacity. It really isn't that far behind the 62 case but it isn't as common either.
Hope this helps,
Noel