Update: turns out my petcock is working just fine - the idiots had it set to PRI despite my repeated explanation how the damn thing works (guess there's a reason they're called grease MONKEYS). Now I'm waiting on the valve adjustment results.
Having read through Markus' thread on petcock rebuilding, I'm starting to like the filter idea. Might look into that just to be on the safe side.
Maybe I'll start tooling up and getting my own garage as well - if you want something done right, do it yourself.
Cheers! V@