The best way to do that, is to find a Brno 21/22 series "donnor",especially one of the very rare "roundbolt" late models.
Finish that nothing made will excel, small ring REAL "Patterne 98", both roundtop and very desirable double flattops, cut for excellent rings that Talley makes and all the bells and whistles.
I like to install a new Oberndorf style bolt handle, three pos. safety, Lapour, Satterlee and even Dakotas are nice, then change the usual DST as I hate the buggers to, the ONE-stage old FN trigger and change the bottom metal and follower.
This costs LESS than all the work you need to do on a VZ or G-33 and you then have a superior light Mauser action to work with. They are not as common as beater P-64s, but, I and several guys I know find them regularly and build on them, I like .280Rems. on them, but,have seen a .338WM and now a 9,3x64B.
G-33s are VERY rare here and a finished one will set you back some major coin, say $2500.00, where I can mod a 21H for a few bucks and their only issue is the off-standard barrel threads easy to have fixed.
BTW, the 7x57 and it's progenitor, the 8x57J and later, 8x57JS cartridges are the SAME length, the case is the same one. The only difference might be a slightly longer cartridge due to a specific bullet loaded, however, the magazines for both are identical in Mauser rifles.
