No experience with them, other than to look at some of their work, but maybe contact Martini and Hagn (google is your friend!) and see what they have to suggest.
Depending on what the gunis, and what needs to be done to it, the "best" or even a "good" choice, may well be someone somewhere else on the planet!
Shipping is cheap, in the scheme of things. It'll cost you a lot to recover a truly fine gun from a hack job.
Cheers
Trev