Anyone heard of A Pierburg 1B3 - number 055 129 024N

Weird one this. My golf came relatively original and had this carb fitted. Can't imagine anyone ever changed it as so much of the car was standard.

Looking online, it's listed as being for a JB engine code which mine is:

https://www.tav-autoverwertung.de/shop/Vergaser-Pierburg-1B-055129024N-VW-Golf-Jetta-Scirocco-15L-JB-Solex-717627160

However the weird thing is, this carb has a fuel return from the float chamber and the JB Engine with the vapour trap has no where for the fuel return to go. It was poorly blanked off originally.

It also had a hole in the choke flap for the boost fuel injection while the correct one is a completely closed choke.

I ended up replacing it on my car with a very similar Pierburg 1b3 - 055 129 025J, which has no float chamber return so works much better in terms of fit and finish.

The weirdest thing is my carburettor manual has no reference to any carb that matches that identification number.

Is it a rare carb for earlier golfs, or was it incorrectly fitted at some point by a previous owner?

See attached photos of the carb manual and the one I have fitted which matches my engine code and specifications.



See below for the two carbs side by side.  


055 129 025J on the left.

055 129 024N on the right.




End of the day it doesn't matter (I think!) as my carb works fine and doesn't have a fuel return blanked off with a piece of rubber hose - just wondering what car this carb should go on, or if it should fit my car and the fuel return was incorrectly blanked off?