I have been searching for a final production NOS AMF Swimaster MR12 for a few years, and was recently able to purchase one from a seller in Hawaii. The final version had 3 LP ports on the first stage, and the all chrome, bullseye pattern second stage cover.
This particular model is uncommon, as most divers chose to purchase the MR12 II with the VAD (Vortex Assisted Design) second stage. This is only the second such example that I have handled.
Now, I need just one more reg to complete my collection. That is the original version with the second stage marked as, "AMF Voit Swimaster Titan II MR-12".That particular example was built in early 1969. Karl has one that is finished in the non-magnetic manner. If anyone has one that is available for sale or trade, please let me know.
Here are a few photos to illustrate the late production MR12. You can see the additional LP port on the first stage.
Greg