Today, I bought a set and went to pick them up curb side.
On the left is an original used Hella, and the SMC repro is on the right.
Click to view attachmentFirst, like the product picture, these didn't come with the mounting screws.
I have joined a picture trying to show the differences that I have noticed. The back side is flat, which I think is normal. The Hella has a radius, but I believe this is due to the long term mounting and over tightening of the lens.
The Repro lens is a little shorter by about 1/32".
The Hella optical diffusing features have sharp ridges whereas the repro's ones are more radiused. This can easily be felt with the bare finger on the backside or the lens.
Also, the area for the screw is slightly different.
Click to view attachmentThere was a 10% discount so a nice total of $32.66 all in for the pair.
So far so good, time will tell.