Leon,

a good choice! I'd make my choice with the 3a: Better difficult to see lines than "astimating" the borders ... especially iwith the more near range between 1 and 2 meters you will have a clue while aiming. The LEDs you will see easily with a bit of training. Don't expect too much from some editors of a magazine;-)
The quality of the Nokton is far out of debt, like all the others out of the "classic collection" ... except I'd prefer the 35mm if you will also, try "point and shoot", a bit more depth of field and a bit wider angle.

PErhaps you should give it a try:
I worked some time with a Bessa 2, external LEDs and a range finder on top, suitable for the lenses ... I Lovaed it for point and shoot, the LEDs I could easily see and I could aeasily use the lines. It was the better choice for me as a wearer of glasses.

Horst