Got radiator hose fitted, thanks to Amazon delivering the right tool for the job (hose clamp pliers)…
That handle has been cut to get it in.
Still fiddly as ratchet is coarse and couldn’t get clamp fully loose, but some prodding and cursing got it fitted.
Then I fitted relays properly with dielectric grease on all contacts - the originals were too but obviously factory missed a bit hence corroded and broken pin. Fitting all the electrical connectors and the battery box was a struggle, but after more than an hour got that in and tested bike as good as I can without starting engine. No error codes, the fan worked and instruments and lights worked, except, number plate light 
Bugger, that’s on one of those fiddly connectors, so perhaps I broke a wire? Or perhaps it was like that before and I didn’t notice. MOT due this month, so need to fix it before then. Anyway, fan now works, so that’s it for this thread.
Edit: Number plate light was faulty.