Read this with morning coffee. Interesting indeed, yeah, the Viton tipped brass float needle in mine sounds as equally poorly finished as yours, clearly had been scrapping so a bit stictiony. Hoping filing cured. Fairly convinced float okay, it was nice and free moving. No fuel in it, but I'd liked to have tested in hot water (but couldn't of course). Nor could I check it's setting level under the circumstances. But fingers crossed, either muck or the burrs on the needle bit and now sorted, as things had been fine until they weren't. The other commonality I found was automotive hypochondria. I will spend the next few hundred miles sniffing for fuel now.
Cheers
Mick