Try Buck Parson, topoftherockairguns.com
Rich B.
Your second picture shows a relatively common part. Known in the US as "Dowel nut" and in Europe as a "Barrel Nut"
Tried to post a link but the website refused it.
Just "Google" it.
HTH, keep well and shoot straight!
HM
lets go on the chance you are going to find one very slim and the why is, it is a part that should not break
now the nut is fine but the holder is the problem
can it be fixed to function, i think so with a good epoxy and some imagination
first you need to get the hold back on the round shape and finding some sort of fixture would be need greased tubing of the correct size and once that is done the nut hole would have to be filled and reshaped
i drill bit of the nuts size with grease on it will allow you to fill and form as you twist the drill
but in todays 3D printing that is where i would go just have one made
you can take the part number and call here if anyone has they might
International Shooters Service
Believe it or not, you might be able to find one at Ikea. They have pretty good fastener support, both in-store and on their website.











