Well this is jolly exciting - thank you David Mack for alerting me. I've only looked through the thread once and this is my first, possibly ill-informed thoughts, but here goes.
I agree that's almost certainly 'Waterways' ; no way can I make it look like GUCCCo. It's hard though to square that with what does look like three female crew.
There's no particular reason to think that it is Chertsey. Don't be misled by the current colour scheme. I have no evidence that Chertsey ever was painted like that. On the other hand, I have no photos of Chertsey between 1937 (when that one at Northampton was taken) and about 1963, so anything's possible. It would have to be pre-1960 when the Petter was fitted.
Can we date the men's clothes at all?
Is it significant that the mastboxes and the stands don't seem to be painted?
The motor in particular looks to be in pretty poor repair - does that help date it?
My gut feeling is that it's not Chertsey. I'd have a better idea if it was the stern end!