I think I've bitten off more than i can chew here - that said, I've got 9 of the 10 names and all but one clue entered, so any hints most welcome...
28d. Enrapt, end up roundly grooved (5) - TRE?D ( (5) is the no. of letters entered in the grid, not necessarily the no. in the answer)
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I thought it might be TREAD (Grooved), but I'm hoping it isn't because then I'm a name short.
Also, 16a. Slide uncontrollably sideways? Up north, we provide a motorised sledge (6) - SKIDOO (Motorised sledge)
I can see the SKID (Slide uncontrollably), but how is the rest parsed?