Thanks David, PM incoming.

On the link pin subject - I've had a number of these (genuine) from Dennis Hiller some time back and also from Chambers - they are very expensive for what they are and I've found that many on dismantling (or failing) have bent easily. Checking things yesterday 2mm HSS shank drill bits are a virtually mm perfect fit and as you can get 10 of these Heller German ones for £2 posted on (gives about 30 pins) I might try them simply cut and ground to length and peened over.

Any thoughts?