This is a fantastic project and in the photos it looks pretty professional. The trouble with watches is that they are so small so you need really small components and fine soldering work to put them together. I've never done anything like this. However I once had a calulator watch (remember them?) and the strap broke. Since it was not replaceable I thought I'd do something else with it. I installed it in my car, in the ashtray, with a single NiCd cell for power, charged off the 12V. I replaced the original beeper with a transistor and small speaker. I got it beeping on the hour and got some funny looks from passengers when it beeped and they'd say "What's that?" and I'd proudly show them.... I was such a nerd :-) It was useful for calculating my gas mileage though.