Different versions of 4,5" Fuchs

Today I recieved two 4,5" Fuchs that I have bought on.
Upon a closer examination I see a couple of differences:

On one wheel the spokes have a tighter radius on the edges and seems a little more flat, compared to an early 6" rim. The other wheel have spokes that are identical as an early 6".

On the back of the wheel the area inbetween the reinforcement around the lug holes are slightly different (the one looking like an early 6" have a fatter reinforcement).

Both wheels are 4,5"X15" and have the Fuchs stamp. They are unrestored and have the original anodising and the rather odd 1967 paint pattern.

My qustion is: What is the story behind the differences? They are obviously made by different tools (or a modified tool). Are the "earlier" type more rare? How long was the earlier type produced? I would rather have two of the early 6" look to match my rear wheels.

My guess (from working some years with product development) is that the tooling where changed sometime during the 1967 model year. The alternation of the spokes where probably made to get a smoother forging process, by the larger radiuses. The heavier reinforcements where probably an attempt to improve the strength of the wheel. Can anyone confirm or deny?

If you look in the webbing you'll find your date stamp of mfg. The ultimate would be to match all your rims with same... Call Harvey Weidman (Weidman Wheels) in Cali..... he'll probably be able to help you .