Mill fixture to hold stock for milling inlet for bottom metal

What does everyone like to use for fixturing stocks upside down in a manual mill for inletting for bottom metals?

 

I am just a hobby gunsmith but my 4" vise with padded jaw inserts worked very well for the stock I had to inlet.

 

They're all different, it seems. So, a fixture is of little help. I find that I have to set each one up individually. Now, one may well be able to set up for a given stock close enough, but I never get to do enough of the same stock to say if the molds are that close but I suspect not, at least in many cases. At least enough that you'd need to check every one. Just my 2 cents, even within the same manufacturer and design.

 

2 x 6" Kurt vise.....of course my stocks have no curved lines.

 

I've got a 4" vise that I use for most other projects but this will be my first time machining the inlet for an M5 (everything else is cut except for the bottom metal). I guess my concern is in the angle of the 2 small surfaces that make contact with the stock at the pillar locations. Are those two surfaces on the same plane such that the only adjustments needed would be in the Z axis to get depth correct?

 

I used shims in the vise to get the stick lines up.