Good evening, gentlemen.
You seem to be correct in your eatimation of the mechanic's prowess. I got a call about 12 to say that the bearing was done & the car was ready to pick up. Wahey, I thought. Went over, paid my £56, and then took the car back to the garage before I even got off the forecourt! Strange rubbing/grinding noise was still there. Ended up talking to the guy who did the bearing, took him a little way in the car to demonstrate. His response was that he hadn't taken the car for a test drive himself (implication - someone had) so he hadn't heard the noise. Had a look at the wheel, and then he mentioned something about seeing a shiny patch on the suspension & rubbed-down section of the wheel....
Drove the car home very very slowly, to the smell of burning rubber, to find that I couldn't get the wheel nuts off because they'd used an air wrench or something. So, another tow truck arrives, loosens the bolts with the aid of a bit of scaffolding pole, and I've changed the wheels back to the originals. Going round the block, the noise seems to have gone, but my confidence is a little shaken, particularly as I'm towing tomorrow for the first time, and it's 50-odd miles to the storage site! I'll let you know how it goes if/when I get back...
Mick, you're right - towing in the dark probably fine. However, as it's my first time

I'd rather be able to see what I'm doing!!
Thanks for your support, guys.