With legacy lenses (i.e. manual focus), it's important to have a good viewfinder.
I second that : you can have great deal on the E-P1 (which I have) right now, but it is not so great with Manual focusing lenses. The main problem is that you won't be able to focuse in bright sun using only the lcd. You need a camera with a good finder in bright sun. and the E-P1 doesn't support the wonderfull VF-2 which you can have for the E-Pl1 or E-P2. So I'd say that among the MFT cameras, your choice is between Panasonic G1, G2, GH1 (the viewfinder of the GF1 is said to be of lower quality than on the Gs) and among the Olympus : E-P2 or E-Pl1.
As for the Bolex-Paillard thing : it is an old movies film camera. The lenses will probably not cover the whole sensor of the MFT bodies.