There has been a vintage Omega rubber strap, Isofrane style, on eBay forever and ever. At $279, without buckles and keepers, a little too expensive. But... buckle and keepers are available separately, so I took a chance. My offer of $229 was accepted, and I got a buckle from Authentic Watches and the keepers from Otto Frei. The keepers are from a recent Seamaster strap and are marked Omega and Seamaster. I suspect the originals were unmarked, but this way is more fun.

The strap arrived today and I assembled everything and put it on the Seamaster 300. Very comfortable, and more importantly, this strap tapers in thickness, so the weight of the rubber doesn't overwhelm the weight of the watch!

Quite pleased. Looks good, feels good, doesn't take a half hour to put it on and take it off, like some rubber straps.

Hope you like it.

Tom

 

It looks cool on your SM300, you don't see many on isofrane. Is the strap itself signed Omega?

I was thinking about putting together one with a generic isofrane band along with a genuine omega clasp like the frakennatos out there to save a hundred odd quid.

 

It is indeed signed. Its part number appears to be CA4752001. The thinness of this strap is what makes it... it's only 2mm once away from the spring bar ends. I've had another of that type strap and because it's 5mm thick, it overpowers the watch.

Tom

 

This picture shows how thin the strap is and why it works.

Tom

 

Hah I had the tang upside down in the buckle. Fits a lot better now.

Tom

 

I can't remember the details, but I seem to remember someone tried this and said the OEM tongue didn't hold properly in the ISOfrane holes (and putting the ISOfrane tongue on the OEM buckle didn't work either). A few years back I was thinking of doing the same thing...

 

This strap is still available from Omega - not sure what you bought is really vintage, but it seems to work well.

 

The holes in the Omega strap are cut on the slant and the tang is at the same angle, so I wouldn't expect them to fit.

Al, I assumed vintage. Hope I didn't overpay too much.

Tom