Seth Thomas used the Gruen teletime/Westclox Quartzmatic/American Microsystems modules in their early field effect watches (same module different names) so I'd guess they also used the same source for their for their DSM watches.
There's also a very similar DSM Quartzmatic under lcd watches on Peter Wenzigs Magic Digitals web site.
http://www.digitalwatches.de
It has the same button configuration so I'd say it's pretty likely that the Seth Thomas watch has the same module in it.
I had a bid on it myself but didn't go beserk as I've had lousy luck with none tested DSMs in the past . If it's working or fixable then I reckon someone on here got a bargain (but it's a total lottery with those pics).