Ah, I searched for gaiter not diaphragm (diaphram)
I'm interested in the 1-2 day comment, particularly the 1.
One UK yard has said "The job will take approximately 2 days to complete" and quoted labour at £920.
The French yard has quoted for the following:
Arrive at port, 'displace' engine, decouple, remove prop, clean up, drain oil and then take it back to their workshop ... (5kms). Labour 8.5 hours at ?43 ph, ?365.50
Remontage platine!? Change the joint etc etc, revisit port, refit. Labour 6 hours ?258
Next day! Visit port. Basically reconnect engine electrics diesel , assist the crane driver, take for a test run. Labour 4.5 hours ?193.50
Total of UK quote less crane £1182
Total of French quote less crane ?1410 ... "£1100"
The parts prices seem very similar so I guess the labour time is too = 2/3 days.
The French quote also mentions removal of woodwork, I'm not sure if on some boats this is structural or not but on my 34 there is just a piece of wood screwed across the boat, 5 mins max.
Thanks for all the advice.