I've bee thinking of scoping a 303 I have. I talked to a friend who's expertise I value. He suggested replacing part of the rib with a Talley base and Talley rings. I think a competent 'smith could make it look almost invisible.

If the rear part of the rib is solid I could have the rib itself bevelled a bit and use Kimper type mounts or have new mounts made for about $300 to fit the rib/bases.