I can remember this topic coming up a few years ago somewhere..
One possible brought up was that the the 043 mid year change took place b/c the US exports were becoming a large 113 market place and US/DOT demands started to get into the production line.
The rubber knobs were collision/passenger safety protection design and US mandate , so it may just be that they got the rubber to satisfy US Import and the Euro production just kept using the acrylic til there were no more ..
From there , they prob all got them , regardless of version.
Maybe that is why they are NLA in acrylic...over the years , I have seen so many mistakes in all the lit, that seeing is believing..
Another mystery........
