gregc - If you're handy, I saw this thread on Savageshooters a bit ago. Is this what you're looking for ? Looks DIY-possibly ? Just Drill & Tap and buy an adapter. Another option I saw some forum is to put a large 'split-knob' that slips over the OEM and screws on. It may need some 'filler' 'cause they're made for Rem 700 size bolt-knobs - they're avail on amazon like $20 or so. I recall seeing them in anodized colours, but I can't find any now. If I run across them I'll post or PM.
http s://www.savageshooters.com/showthread.php?69788-Question-about-B22-bolt-handles