Warning: Extreme Geekdom Ahead.

So, a final word on the "230" font on the back side of the housings. After looking at the photos from 70SATMan, I was inspired to get to the bottom of this (tiny) issue once and for all and I spent a couple hours at my shop today looking at more NOS and used units (including U.S. and Italian versions) and pulling the turn signals from half-a-dozen SWB cars in my collection. I also looked at probably another hundred photos online and I have what I believe to be the final answer.

On original Porsche SWB turn signals, the 230 font is different between the driver side and passenger side housings. Specifically, ALL driver side (left) housings use a font with a flat-topped 3 in the 230 while ALL passenger side (right) housings use a standard 3 in the 230. This appears to be true across all years of manufacture and all versions (Euro, U.S. and Italian). Of the nearly 100 turn signals on my shelves and on my cars, ALL of them follow this rule and every photograph I was able to find (including those posted by 70SATMan in this thread) show the same.

The new Porsche Classic units use a standard 3 on both sides meaning that their passenger side units are correct while their driver side units are incorrect.

Yes, I know this is a silly detail compared to the housing, color, and BOSCH font issues but the pandemic has resulted in more free time in my life and this was more fun than cleaning my garage.