well, just in case some of you still haven't figured out how to get working flashing leds, i just found some parts to build this myself. if my memory serves me right i heard a lot of folks had a problem finding those switches.
i went to an electronic store and bought a flashing kit for model trains, unfortunately those run on 12 volts, but the good part is there are tiny 12 volt batteries available and 12 volt leds as well. all parts had cost me a little less than 20 bucks, already had some wiring an solder at home, and went at it. the entire build fits easily into a terminal fettler rangefinder.
no wires to run through the stalk. rangefinder goes down, leds start flashing. rangefinder goes up, leds go out. i installed a yellow led on the inside as well, but that one turned out to be rather weak, so i'm gonna change to a brighter white later on.
the store i bought from ships worldwide, online presence can be found here:
and here is the parts list of the stuff i used:
2x 12volt red led part no. 182451
1x 12 volt yellow led part no. 182486
1x switch part no 700444
1x 12 volt battery a27, part no. 626740
1x flashing kit part no. 210995
you don't have to use the yellow led if you only want the red led's in front to flash. besides the parts above all you need is some wires, solder, soldering gun and some patience ...