Hi, Have a GMT (early 70s, model 1675) that gains about 7 sec. per day. Is this acceptable and is there a way to regulate it? Any idea on value? (It's steel, plastic crystal, Oyster bracelet). Thanks.
I think this is actually pretty good and within chronometer specification of the era, so don't touch it. I don't think a brand new one will do better than +/- 3 secs per day. Value is probably around $1500.