Would like to have an Auto 5 French grayed. Anybody have a solid recommendation?

Send it back to Browning in Arnold, MO, let the pros do it right rather than trusting it to a 'smith not familiar with the process.

Give Art's gunshop in Missouri a call.

Briley lists it as a service.

HERE

I would also call Turnbull - his place does a lot of old style finishes, if he can't - probably know who does.

$795. to French Grey is extremely pricey !

any Polished blueing these days is $600+…. Even bead blasted blueing is 500+

I don’t think the French Gray is all that rust resistant -but people normally do it to show off engraving anyway.

I believe Arts Gunshop does it. They are true craftsmen. And, their specialty is Brownings.
Good luck!
https://artsgunshop.com/