It wonīt work as well on a Leica since the frames move significantly while correcting for parallax.
I am not so optimistic about fixing my rf patch. Unless it goes to England.. and i donīt like fixing things out of the country. Itīs always annoying.
Customs here where i live will try to charge it as an import.
I cpuld find a beam splitter/ prism for the viewfinder but fixing the patch involves replacing the entire rangefinder.
I will keep using it as it is and miss some pictures untill i find another M3 body.