ridgerunner,
Get yourself a couple of LH Model 70s in .375H&H. Keep one as a .375, and build something on the other (e.g., .400H&H, .416 Hoffman, .416 Remington, .458 Lott, .470 Capstick).

The rifle in the photo below is a LH Model 70 .470 Capstick, built on what was once a .375H&H.

George