Glad I was on Oxygen... Nearly died laughing as a 2b I was following tried to enter a thermal. Full aileron, full rudder, nothing happened until hitting the sink on the other side, then it started the turn in sink. The flap hinge in the 2b is the upper surface flexing - which you can imagine takes some force - so there's no aileron modulation of the flaps. I found pushing the stick forward helps get some aileron and rudder, not quite how you'd normally enter a thermal.
Doubt you'd ever dare "rock polishing" in a Jantar 2b, the Nimbus and 17 can be better trusted in close quarters.
The similar vintage Nimbus 2 (especially 2C) is easier to fly. For earlier ones with a "flying tail", get your CG forward until well familiar. ASW17 is easier still, handles like a 20 in flight.
Nimbus 2s are the only one in your list which include a canopy hinge from the factory, the other canopies come right off.
I prefer rigging the other two. But as you said, a one-man rigger will change things. With a reasonable trailer and rigging aids, older open class gliders can be rigged on a daily basis. Jim Madsen, Joe Gera and Malcolm Kyle all used to rig their Jantar 2bs by themselves from Minden Fab trailers with the Stowers one-man rigging setup.
Joe once flew 1000k, had a barograph failure, and did 1000k again the next day.
But my 1983 Soaring Magazine Sailplane Directory used to fall open to the ASW17 page, if that tells you what I'd get - and did.
Jim