I recently received this GP manual wind in for service... The gold tone crown that is on it is unmarked, and clearly not right for the watch. There is what appears to be a serial number on the outside of the case back, but otherwise no case number that I can see - not sure how this brand works in that way, so maybe they only use case serial numbers. Here's the movement: This is clearly a snap together watch with little water resistance, but I was a little surprised to see that the case has no case tube: So for anyone who is familiar with these, is this case missing a case tube, or is the crown supposed to have a part of it's diameter that goes into this hole in the case frame? If you have examples of what a properly marked crown would be for this sort of case, that would be helpful also thanks. Cheers, Al
If inside the case back is not marked GP, I would guess that the movement came from a scrapped gold watch and was fitted into a contractor case. I vote case tube and water tight crown. Best engineering solution. Here's a pic of inside a generic GP that I have.
Maybe this style would be ok? It has spring inside. On picture spring does not work but you get an idea how it works
Thanks - the case back is marked in very much the same way yours is, but no case number inside - only an 8 digit number stamped on the outside of the case back, that I am taking as a serial number. Yes, and I've seen GP marked crowns on eBay that would fit this style, like this one... https://www.ebay.com/itm/GIRARD-PER...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649Purchases made through these links may earn this site a commission from the eBay Partner Network Some even seem to have a sort of seal (maybe - looks like some sort of seal in the side view) that would go inside the hole in the case, like this one: https://www.ebay.com/itm/GIRARD-PER...m=312062347818&_trksid=p2047675.c100005.m1851Purchases made through these links may earn this site a commission from the eBay Partner Network I'm just not 100% sure that this is what is supposed to be there, or if it's supposed to be the style for a case tube, and I need to install a tube. If I could say with some certainty that it is or is not supposed to have a case tube, I could then go from there... Thanks to all who have responded so far BTW! Cheers, Al
First let me start by saying that your case is not missing the case tube, those cases were originally designed like that, it was a "dust proof" system which supposedly prevented dust from entering the case (in reality this was the exact opposite, the cases always ended up full of dust and dirt) All Girard-Perregaux cases should be marked with the Girard-Perregaux logo: Some case backs aren't marked on the back. Regarding the crown, this is the correct crown for the watch you're repairing: PS: If you need one I can send you the crown from the picture free of charge (I would only charge the shipping), I'd be glad to help a fellow watchmaker.