One of the watches introduced in 1968 was the Accumatic A-509. It was also offered in 1969. Information is scarce regarding the model lineup after that so I don't know if the A-509 was offered in 1970 or later. I don't believe so.
The A-509 came in a stainless steel case. All 5XX series models come in a stainless case. The bezel has very fine reeding along the circumference and the crystal has a faceted diamond edge inside.
Under the dial is a 17 jewel Hamilton 694A movement. This Swiss made movement was produced by ETA and is identical to the ETA 2472 grade but with Hamilton markings.
I recently purchased an Accumatic A-509 and it happened to come with the original JB Champion bracelet. The diamond-faceted crystal is a very nice detail but a challenge to replace. Mine has a crack along the side of it that has collected some dirt. It would look better if it was replaced but this watch would lose something with just a plain crystal.