Leon, the best choice for use with the 40 Nokton is the Rollei 35 RF, which is essentially a special edition of the Bessa R2, but with 40/50/80 frame lines & with the same improved close focus capability (0.7 m) as the R2/3A. It does not have AE, but the upside is that it's not battery dependent. Pre-set your shutter speed & you essentially have AE for most situations.

The Rollei shares the same 0.7x magnification as the viewfinder in your old Bessa R & the viewfinder for the R2 & the R2A. In this viewfinder, 40 mm frame lines are even easier to see than 35 mm frame lines are; I have no problem even with glasses. In addition, this viewfinder is parallax corrected for a 40 mm lens. An R2A will not be; its parallax correction will be for 35 or 50, depending on which frame lines you use with the 40. Further, a nice benefit of the 35 RF is that none of the Rollei frame lines does double duty - so, no clutter from 90 frame lines in the middle of your 35 field of view.

The difficulty of seeing the 40 frame lines in the R3A is a serious drawback IMHO. One of the benefits of rangefinder photgraphy is that you can see outside the frame lines when composing. If you can't even see the frame lines themselves, you obviously can't see outside them either. Of course, you can work around this by estimating, etc., but this wouldn't be anyone's first choice.

The strength of the R3A is for use with fast 50s & with teles. They provide 40 frame lines in order that you have the option to shoot a little wider, but this camera is not designed for use when a 40 is the primary option. In my experience, the Rollei 35 RF is the ideal RF camera for use with any 40 mm lens, including the excellent & compact 40 Nokton. A bonus is that it comes with a 2-year manufacturer's warranty, serviced by Rollei-USA.