Daveh hi, I have a W & S cylinder plug, brand new in the white, has slot machined in for screwdriver and 'do not remove' engraved also; not sure what models it fits, but I guess it's pretty standard across the range of larger pistols. Value - I have no idea, if you are interested e mail me an offer, I won't be offended, in reality it's worth what you want to pay; the part was never offered as a spare after the change of 'service' from rear to front stripdown, as it was then a fixed part, so an up to date price is difficult.
E mail me at ray210645@yahoo.co.uk if you are interested. I'm on hol 'till Mon 24th so can't reply before then.
ATVB
abellringer