I was not able to find the locking window trim  (or glazing I find it is called).  Some things from 1975 just aren't made anymore.  So plan "B" went into effect and I had to figure out a way with 2013 materials. Relying on Home Depot, as is so common in our time,  I was able to find:

1. 1/2" Clear Acrylic
2. High Density Foam Weather Stripping
3. Silicone II

Next I had to figure out how best to cut this stuff.    I first tried the multitool but that wasnt working very well.   I found a great you tube of a guy that sounded like he was from Australia doing it very easily with a skill saw and a jig saw.  So, after another pilgrimage to Harbor Freight to pick up those tools, I was able to crank out this test window:

I didn't use the final layer of black silicone because this was a test window - the acrylic in this one was tortured quite a bit in my tool experimentation.

What took the longest was cleaning up the original aluminum frame.  I spent over an hour on just that.  For this the multitool was very useful with a scraper attachment to get rid of 40 years of various glues and sealants.  I then followed up with 120 grit sandpaper by hand and painting.

One problem remains - the black silicone I dont think will adequately obscure the white weather stripping.  So a trip to Lowe's is on deck for this AM to find black weather stripping - or white Rustoleum paint to do the frames in white instead.  (The frames were originally were not painted any color and that just didn't look good).

Later the next day:

Well I found some other trim and I tried to use it, but it was too thick and there wasnt enough room for the silicone to hold.   SO stripping it all down and back to the drawing board.  Last nights idea was the best probably.  Going to repaint all white and try it with the original white foam (or no foam at all).  I have to wait for the silicone to dry fully before I can remove it though.

Stripped down the Port window as well and I have glass ready for it too.