There is the husband and wife team of Jim and Trisha White in Maine as well: http://www.jwhitegunsmithing.com They routinely make double rifles on shotgun actions. And on these forums is Brian Perazone http://www.bpgunsmith.com/

I don't own double rifles and I have no experience with Jim White but I do own a very nice MAuser rifle that Brian Perazone sold me. I have nothing but praise for his products and pricing.

Best wishes!