I lost third gear a while back and now that I have finally pulled it apart my
suspicions were confirmed there was a good sized lump missing from the ratchet
teeth.

Now according to the parts book ( and service sheets ) there should be a wire
clip on the end of the gear change shaft Part 15-4240 which I suspect is to
hold the ratchet mechanism together.
Now I have checked all 3 that I have and none have this wire clip on them and
all have signs of rubbing against the flange of the bronze bush in the front
cover.
Is this correct or dose the wire clip actually do anything apart from holding
everything together during assembly or disassembly.

The reason for asking this is that on both the units that I was going to replace
the broken one with the lower ratchet paul ( the one on the kinked arm ) only
engages with about 2/3 of the ratchet plate and I am loathed to put it back
together and repeat the destruction.