Hi Rich I am in the process doing an Omega up and I had trouble getting a new piston seal to replace the original delrin one , Chambers were very helpful but they only have a new batch from webley and they are CR*P. under sized and to stiff to work properly. John Knibbs has one that fits a treat ( red in colour) I also had a spring off chambers too but its running a bit under power so I will be ordering a J. Knibbs Titian Spring and see how she behaves. Unless someone else on here has a better suggestion for a better spring ?.
ATB
Graham