Indian wrote:The vent tube must be the easiest thing ti find in you local scrapyard.
I do not know where you're located. Indian –
but any "local scrapyard" in my state will NOT have even one BMW motorcycle in the yard.
BMW specific salvage in the US , by and large, is moving on to newer models ...
but, perhaps, worth a try even as they are not "local"
but this will be a matter of an internet business transaction for most ...
to acquire an age hardened and weather cracked bit.
IMNSHO – the new piece may be a better option.