20 mm ends, marked 47. Seems like it would fit a asymmetrical Speedmaster. Finished just like a flat-link. Has no marking on the clasp other than a 73 stamp, which I assume is the date. Look familiar to any bracelet gurus?
Looks like an 1175 to me. The links aren't quite flat like a 1039, but they're slimmer than the 1171. It's essentially a middle ground between the two. Love 'em
I don’t think the Seamasters of the era were 20mm? Most were 19mm? Here’s my f300hz on its original 1175 with 19mm 48 endlinks:
It is at the inflection point between 2 and 3 digit endlinks. I think that it is possible that it originally came on some Speedmasters (145.022), but any 20mm lugged watch from between 2nd quarter of 71 and some time in the early 80s, could have potentially be used on a 47 endlink, as they were supplied at the boutique when someone was purchasing a watch. The 47 end link number is absent from Mstegnas chart, linked above. I would bow to his authority on this one, but I would very much like to see if anyone has a seen a 145.022 that originally came on 47 endlinks.