I was recently taking images of my watches, and had a better look at my Omega Seamaster 300,  ref 2913,   Oct 1958 from the Omega extract.

Its bracelet is a 7077, marked 4/58 on the clasp, which makes sense given the info from the extract.  The 4/58 was the first date stamp on 7077,  as before that the date was not marked.

Then I started looking to the endpieces, which are n.6 – but not normal n.6.    I think these are the very first type of n. 6, and there are some notable differences from the other n.6.

1-  The top of the endpiece looks normal, but it is different because it has a folded part (reported to exist in early n.6). This is supposed to make it easier as it retains the spring bar and last fixed link while fixing the bracelet to the case.

2- The back of the endlink is larger than other n.6, has one single slot and the “6” number itself is more elongated than the usual one.

I have found similar endpieces also on a 2915-1 Speedmaster sold at Christie’s – including the shape of the “6”

3- Another peculiarity is the absence of those subtle grooves in the inside of the top wing,  seen in all other n.6 (except the recent fakes).    There is only a very slight change of colour.

4- And lastly, have observed in early n.4 endlinks (18mm, were used in Rancheros and other 18mm lug Omegas), same difference exists:

They have the folded part, have no groove on the inside of the top part.  Like in the early n.6, there is only a subtle change of colour, perhaps light reflection on the slightest depression in the surface.