Thanks to Adrienevo!
I bought a moderator from Adrienevo which was advertised on this forum and went out and collected it today.
Firstly the moderator was in even better condition than Adrien had described it as and was certainly worth quite a bit more than he charged me for it. Not only that but at no extra cost he even offered to drive out with the moderator and meet me half way in order to save me some driving time.
I got the moderator home and tried the delrin washer which came with the rifle and it fitted like a glove so all is well and I feel that I have got a real bargain.
Many thanks Adrien, you are a real gent and a credit to The Stalking Directory.
Regards and Best Wishes to You and Your Family Adrien.