Full tank of gas, and only 2 hands so no photo... but *I* don't see any way to get into the B4 OEM petcock. It's probably just pressed together for an interference fit and could come apart if done carefully, but most people would end up breaking te cast metal before getting the dumb thing apart.
Anyway, that kit looks like something straight out of a K&L Supply catalog (and marked up a bit). If someone's Truely interested (ditto for the carb rebuild kit), pull up the K&L Supply website to see who's a dealer near you and go pester them. They don't list their normal maintenance items on the website and have a TON of stuff, including fork seals and bushings, carb/petcock rebuild kits, and other general maintenace items.