No idea what part of the world you are in and that probably has a big impact on the question.
It does seem that early Bosch/CAV equipment is becoming difficult to get. Here in the UK there seem to be eastern European copies available ( probably not very good but what else can you do ).
As there so many copies of these engines available I would imagine that copy injectors are cheap and plentiful and changing a nozzle is not worth the bother in this age.
These are low tech engines and will not be too fussy on injectors. Try looking at Utterpower or similar importers and you should find something.
Flux
