Addressing the weak bob weight springs, I removed the A/R unit for inspection, and off the mag, the mechanism worked perfectly, the weights springing back with a snap. I was under the impression that the centre bolt should be removeable, but it seems to be held captive within the unit. The horseshoe washer is in good condition, but the plate with the two holes is distorted on the outer rim, the centre being fine. During the course of handling the assembly I managed to drop it
resulting in slight damage to a tooth on the fibre gear. Most of the damage is to the front / top of the tooth, but the majority is ok. I'm going to use it as I think it will be ok, but I was (and still am) cursing myself for being such a careless idiot.
As a trial, I put the unit back on to the mag and found that as the bolt is tightened it nips up on the bob weight mech so there's obviously something not quite right.
Work continues.................