Gunsmithing Flush-Cups on HS Stock

Its pretty easy to do yourself. Have done 2. No issues.

If again, would use a plate as a washer and try to find a nut to fit the flush cup threads.
Adhere (gorilla glue) some solid material behind where you are placing, drill and thread.
I did tap mine and glued cups in.
Did one I doent glue cups in (was a work in progress when I sold it).

Easy and best option if you arent into tinkering is to send to Jducos.
 
I did one for a friend, glued and a flanged button head screw from the other side of the stock. Yeah you can see the screw head but it's low profile, black and doesn't stand out like a sore thumb. It's held up to a lot of use so far which is a little surprising given the stock material.