Just wondering if anyone knows how much this vintage seamaster is worth?

Its a Cal. 1012 and if i looked up the serial correctly then its from 1972..

 

Are you sure it's a cal 1012?

If you've checked the calibre check the reference in the caseback and search for similar sold items on eBay.

 

It looks as if it is a 166.0172. For the rest, as above.

 

yes it is 166.0172.

i had a look but could not find on eBay or info in general about this reference.

 

If it's really 166.0172 it's a 1012. It looks in pretty good condition. For the value I would say 500 to 600 euros.