Thanks mark for this amazing reply!
I will try to get the picture up tmr.
And just wondering do you have any suggestion on a watchmaker near canada or US?
I think it will need a total overhaul ....

Jeff z

: It's a bit early to have the model reference as well, so if there
: is only the serial that's fine.
: Could be either at this point. For a mainstream Carrera it's more
: likely to be signed, especially if Carrera 12 it seems, for a
: Dato 45 it would be unsigned. For a 3647 it's a bit pot luck.
: 6.4mm diameter and it should be relatively thin. If you look at the
: OTD gallery index page for the 3647, the first S index photo has
: the correct crown, but the N's is incorrect - it's much too
: thick.
: Used to be hard, but a bunch have been on eBay lately.
: You need a "direct" image link from a photo host such as
: Imageshack or PhotoBucket. Paste that link here, highlight the
: whole text and click the button that looks like a painting. That
: tells the forum it's an image. Use preview not post to make sure
: it's showing correctly before committing the post.