Split Alpina wheels exist but are different looking than today standard Alpina.
Racing wheels Alpina from 70s and 80s was multi piece wheels but are hard to find and very expensive.
Realy dont know that, maybe someone with more experience will know?
But wierd is that is 73 year ans Bosch plaque with Made in Germany ( not W.Germany )?
Try to send mail to Alfa1750, his website is Rocky s.r.l., write on Google.
Eurocarb I think cant help, they have a lot less spare parta for Solex and other than other suorces.
I have check and apperas that are inside 6.6 mm pistons, I have measure with manual caliper.
By that it is probably standard pump?
On pump body is stamped yeat 73? But Bosch tag plate?
Yes I know about relation KF and Bosch.
I dont know about purpose of pump but if we connect on fuel cone which is marked BMW V7 think that is road pump?
But never seen with this Bosch numbers?
At moment pump is modified for use in racing purpose on different brand engines than BMW, but I have all original parts removed from pump if will be needed.
Paint remover, like nitro will do work good, but you need to disassemble carburetor and leave in some can filled with liquid for some time, best is after to wash with water on pressure.