If this helps, I put a 10” 419 rail on a manners eh1. Not flat or even remotely made for a full length arca. I drilled the holes where they needed to be and installed the T nuts from the inside all this like a typical installation. Then I taped off the stock and roughed up the stock surface under the rail. Waxed the bottom of the rail and put a skim coat of devcon under rail. Put rail on and installed screws without tightening beyond getting the rail in place so I didn’t bend the rail but let the devcon fill in the void. Basically no different then bedding a scope rail to action back in the day just with more devcon. Worked like a champ and ran two seasons of nrl hunter without anything loosening or problems. Hope this helps.
