Help with IDing a vintage Rolex

What do all of you find wrong with the movement, pray tell? This movement is a calibre 1200 which is very much like the calibre 1210 which is the one with the sweep seconds hand. In my opinion, this movement is NOT a sweep seconds version calibre 1210 converted to a calibre 1200! I have included a picture of my calibre 1210.



To convert a 1210 to a 1200 is not simply a matter of removing the sweep seconds parts, and changing the dial! To do that conversion, one would have to replace the third wheel which has the extended top pivot that carries the centre sweep pinion drive wheel. Also the fourth wheel would have to be changed for a fourth wheel with the extended bottom pivot which carries the seconds hand. Also, the centre wheel with the hollow arbor for the sweep pinion would have to be changed for the centre wheel with the solid arbor. Then of course, the dial. Please note that the picture of my calibre 1210 also doesn’t have a serial number. Clearly, a lot of guesswork going on here! These movements were made for Rolex by Aegler with whom Rolex was associated. I have two Rolexes with the calibre 1210 movement. This calibre 1200 looks legit to me.

The pictures are lousy, but I think you should consider jumping on this, provided you are comfortable with the price, and are prepared to have it serviced. On the other hand, if you aren’t eager to own it, and you live in a large town and don’t want to expend the effort to go get it, give us the name of the town and the address of the seller, and maybe somebody else will scoop it on you.

I have no explanation for the case style number difference. You won’t find the caliber number or serial number on the movement. All you will find behind the dial is the Rolex name. Such a conversion as was discussed would not happen. Did the original 1210 movement rust, or was otherwise damaged beyond repair, to be replaced by the 1200 movement with its dial from a donor watch? Had that happened, perhaps the case that movement was in was likewise trashed, and someone “Married” a donor movement and a donor case? How likely is it that such a marriage took place? I leave you to use your imagination on that. Was a case back switched with another Rolex? Could be, I suppose. Or did this Mix up happen at the factory? More likely, in my view.

Since my first reply, I have gone back to my Rolex guide, and discovered that your movement could also be a Rebberg calibre 700, not Aegler. There are several characteristics of this movement that match yours better than the 1200 did. Both firms were associated with a Rolex. The Rebberg 700 movement is 10 1/2 ligne diameter, (or 23.7 mm) which could end up in a 30 mm diameter case. There is no listing for this Rebberg movement with a sweep seconds hand. The plot thickens. The watch looks okay to me. As to mechanical condition? No way for me to tell.

It’s common for Rolex to use casebacks for similar models. For example, one often finds 5512 casebacks on 5513 watches. The same is actually true of some bridges, and one often finds 1570 bridges in 1575 movements. They are notorious for using what is on hand.

I would take a close look at the subdial. Even in that blurry photo, it looks a bit suspicious. This is not a highly collectible piece because of size, and IMO the only reason to buy would be if the condition is very appealing, like the one that @Canuck posted. A redial of this reference would not interest me at any price.

If that is a Rebberg calibre (Rolex calibre 700), there is no equivalent model shown in my reference as having a sweep hand. Any similar a Rolex of the era that was in decent shape, and HAD a seconds hand, would be more collectible in my opinion. For $750, since this is a bit of an obscure watch, the seller is not likely to find them lining up at his door. You are likely the only one interested in that watch that now knows as much about it as you do. Why not give him your phone number and tell him to call you when he gets to xxxx dollars (your offer).

P. S. It could also be a calibre 600. These manual wind movements of the era all look very much alike. The calibre 600 likewise is not listed as available in a centre sweep seconds model. The calibre 600 is a 9 1/2 ligne (21.2 mm dia.), and could also have ended up in a 30 mm case.