With massive thanks to dampking, I picked up a whole heap of goodies for next to nothing.Oh and Sanket, I found a place with brass bits and bobs as well as a whole heap of older spares in Russel market. I'll send you his number when I remember where I put his card.
I tried to tip the bike side to side to shake out as much of the old dino oil as I could. I replaced it with about 1.7 quarts of synthetic, up to the middle of the glass. After riding it, it's settled out to higher than the glass - not too much higher, as it doesn't take much tipping to the left to see the oil level top. So my bike makes extra oil, rather than using it up...