For anyone needing to replace the "shift finger" - casting and plastic ball that goes onto the gearbox selector shaft (the plastic disintegrates after many years...), I can report that its extremely easy to replace even after ~20 years since the last time! There is a single bolt holding it onto the shaft (which may be on with loctite - depends how much the last person used....), but its not a close fit on the shaft, so after the bolt is out it comes off very easily - and putting the new one on is easy without having to remove anything else (there is plenty of play in the gear linkage).
Part number is 191 711 233.
VW heritage have a pattern part which isn't spot on tolerance wise but isn't bad and seems to work fine:
Link (https://www.heritagepartscentre.com/uk/191711233-gear-shift-finger-for-5-speed-gearbox.html)
VW Class still has some original ones, but takes an age from Germany.
Link (https://www.volkswagen-classic-parts.com/catalog/en_uk/part/191711233?epis=009,064,070,077,092,110,120,121,146,148,159,160,165,166,167,172,184,185,214,236,241&ct=3&q=191711233)
You will need the plastic bush that goes in the housing (191 711 209) - the old one came out easily from mine so could reuse it, otherwise Spanish pattern part available here (NB this is definitely not the OE part whatever it says - not bad but a little short and slightly larger ID):Link (https://www.ebay.co.uk/itm/335710928968)
Its listed on their website, so presumably you could register and maybe get it direct (3RG 24794):link (https://3rgindustrial.com/en/product-level-bearing-reference-24794#)
Hope this helps someone!