Who needs schematics when you have nitric acid? https://zeptobars.com/en/read/Luch-quartz-wristwatch-IC-at-sc-tuning-fork Generally they do have a clamping diode or modified transistor junction across the coil, otherwise the chip would fry.   

Thanks, I have actually just bought that very same book, Practical Watch Adjusting' so will have a study and have another try sometime. I just found out that replacement mainspring is recently obsolete at Cousins UK so I am short of options. I'm actually hoping that it will be ok in actual use but probably won't be based on the evidence.

If it were a manual-wind then I’d say it maybe didn’t matter so much, but the automatic winding does lead you to a potential problem which you’ve obviously discovered.    On the positive side, that’s still a great amplitude to be getting from a Seiko.    I don’t think it would be unreasonable to modify the profile of the bridle slightly if you think the lubrication is correct. I have quoted De Carle’s book here which shows how it is done, though it should be fairly intuitive. 

May seem daft but have you tried giving your oilers a thorough clean.  if they have been in contact with anything containing silicone oil (seal grease etc), PTFE (some oils), or moly/graphite etc, then these tend to 'plate' onto the oiler and prevent proper oil stiction. May have to be mechanically cleaned (ie with cloth or very fine paper) then finished in an U/S cleaner.

Isn't there a small leverage on the side of the movement next to number 5? I've just removed stem from the similar monocoque watch with E766. The trick is to remove it from 0 crown position while it is pressed down. At first it didn't work for me because I tried to do it from 2 position.