Music Babble

Donovan's probably the closest, but Traffic and Van Morrison also strayed into similar territory, and Led Zeppelin too as you mention. But I think the most similar act in the Hall I can think of is probably The Band.

I think Drake has the best shot of this bunch, maybe followed by Thompson who I think would be more likely to get in solo than with Fairport Convention or with Linda as a duo.

I think the American-centricness of the hall is pretty clear when you consider that the Paul Butterfield Blues Band is in over any of these.