I'm unsure of the exact date but I think it's from 1959-1969. The (Swiss) case appears to be solid gold, unsure of the purity. There is a mark at the top of the case which reads 40 with an LL hallmark. The dial has some corrosion that is visible in the picture but not clearly apparent to the unaided eye. The watchband appears to be the original, gold plated Speidel Twist-O-Flex with a little wear on the edges. This was my grandfather's watch, he lived from 1913-1996. This watch was given to me in 1999. It runs well, and I wear it on occasion!
I'm going to suggest, based on the serial number beginning with 1-, that this is an international Ambassador model. I checked the int'l linebook and there are some close matches, but I could not narrow down one with certainty.
I feel 1960 (posted date) is too early for this model, so in order to properly date the watch, the date stamps would need to be verified. The case looks to be top-loading.
40 might refer to 40 microns. I've seen this listed before in many Linebook entries.
We know the model is Ambassador, but I do take Ken's point about it also being an International release.
In the strict terms of an model ID, I'd go with Ambassador as we typically use the International ID for those watches that we cannot determine a name (if it was given one).
We have this Ambassador example in the database that has a similar case back and dial configuration. This example has a internal case stamp of M5 and a serial number less than this example.
Movement is dated M4 and the case is stamped M5, so I suggest we use this year 1965.
