There is a 13mm one advertised currently in the collectors section for £75 including delivery - it has not sold.
The newer 11mm types usually sell better as there are a lot more HW rifles to fit them onto and so the demand is greater although both sizes would appear to be equally hard to find when you need one!
I recently advertised a pair of the 11mm types and the "asking price" was £100 - and they sold OK.
Last edited by zooma; 18-03-2018 at 04:46 PM.
Rossendale Target Shooting Club. Every Tuesday and Thursday evening 7 - 10pm.