Thanks for your answers guys.
I had a top-end done in last December and haven't really ridden that much. :( I'll blame the wife. ;) I checked my compression and it was ~173 psi. It's within the service limit in my manual. If, when looking up the exhaust and manipulating the "operating rod" manually and everything looks ok, can I assume there is no strippage?? If there is no room to remove the main valve, then I guess I'll pull the barrel. But I'm always interested in doing the least amount of work (being a civil servant and all). ;)