Repairing a JG AUG

[OldJanxSpirit]

Never posted before so this is a bit of a shot in the dark...

I am wondering if any one can help me with a small problem. I recently got a few second hand broken AEGs, whilst most are U/S due to poor repair one was recoverable after several hours work, a JG AUG.

Unfortunately only one part was unrepairable as it is completely absent, a small barrel lock ( listed as part TM-5 on Tokyo Mariu AUG or AU-5 on JG AUG).

Typically this part doesnt seem to be stocked by any retailer that I have tried so far and I am wondering if anyone can recomend a seller or if any one has a broken or U/S AUG and is willing got sell this small part.

I cannot post attachnents of this assembly (no idea why atm), which consists of a small 13mm diameter cylinder with a small spring in its base and a button mounted via a thread on the side.