Why all the talk about upgrading?
You certainly won't upgrade a watch that requires a degree in swiss watchmaking just to dissassemble... Repair duff screens, and change the battery after a year when it's fsck'ed defo, but that's as far as I would be willing to go and waste my time (but I'm quite happy with my Seiko and Hamilton automatic watches that do their job, need no recharging, and are globally maintenance and upgrade free...)