Any good ? http://www.pullthetrigger.co.uk/Air-...sembly-QD-Stud
https://www.ant-supplies.uk/rifle-bi...sory-stud.html
Part way down the page http://www.airgunbuyer.com/Showprodu...%20Accessories
again. part way down the page http://www.rowanengineering.com/products15.htm