That\'s a beautiful watch? I read the new 300\'s were based off the original Seamaster, made in 1954 I think. That would be a wonderful addition to the collection, but tough to find I imagine.
I just got the 1973 Seamaster today so doing an in depth comparison would be a bit hard. The first thing I noticed is just the sizes of the watches. The '73 model is a 38mm and the '15 is 41mm. Both are Automatic movements but the exact movement of the '73 I'm unsure of at this moment. The '73 seems