http://www.mayfairengineering.com

What is the story with the Mayfair Engineering Mauser action?

I'm thinking of having AHR build be a little 7x57 to go along with my GMA auctioned 375 H&H he's working on. I don't think GMA makes a small ring action suitable for a 7x57.

If the Mayfair is not the choice, what should I use?