Nick -
I dunno which side of the Pond you are, but: i have a canonet 28 with cap and hood, very stinky case, papers and everything except box. I ain't sure it's the same cap and hood as used by the G-III QL (17 i guess), but if it is, you can have the whole thing. The camera itself looks weared but is working, - ho,wever obviously it's not a QL-17.
I got it for 5 euro + postage, put new light seals and cleaned it a bit, but I ain't using it at all. Make an offer in PM if you're interested. I'm in Europe, Netherlands.