It also depends if it is the mark 1 or the mark 2.

The mark 1 can be easily identified as it has the eccentric cam that can be rotated to give the best fit under the thumb web part of the hand.

The later models only had a simple tube here but also had a barrel weight that was held onto the underside of the plastic cocking sleeve by two self tapping screws!

The rotating plastic collar that is used to make cocking the pistol more comfortable is prone to break - and these are no longer available as a replacement part!!

Model 10 and 6M pistols that have this plastic part that is either damaged or broken would now be more (very) difficult to sell at any price so this needs to be checked carefully before any accurate valuation can be given.