[Leica] 3.5F repair question

[langhans at compwrx.com (langhans)]

I have a 3.5F and I discoverd it has a problem in that the double exposure
over-ride lever does not work.  I had it in for a CLA a number of years ago
(over 10) to a place in Seattle (not sure it is there anymore - somwhere on
N 5th Ave between 145th and 175th.) when I was going to summer school.  I
remember thay had to work on it twice.  The first time I got it back,
something didn't work (I for got what) so they fixed that.  It has been
years since I wanted to use the double exposure lever, but the other day I
tried and it does not release the film wind.  I was wondering if this is a
simple repair that I might attempt or does it need to go in to a reputible
repair service.  Is it just a matter of hooking up a lever that they forgot
to hook up or does the whole camear need to be disassembled?

Aram