a 30-06 M54 uses the same magazine box, receiver hole spacing, ejector location, and guard screw hole spacing as a pre-64 model 70.
If you can get the proper magazine box and follower (wisner?), converting a 30-06 to 300 H&H would be no differetn than converting a 30-06 pre-64 Model 70 to 300 H&H, not that it is easy, quick, or cheap to do so.
I have a ~1931 (pre-speedlock) 30-06 with the factory stainless steel barrel I picked up for around $300 a few years ago, it is a neat rifle, and shoots very well. I have a spare p64 M70 bolt and will retrofit the safety and shroud one day to the M54
