There is a pretty good sl113 wiki about the clock but also look at this. The early 107 analog clock is pretty much the same clock. You can see the wire you are talking about still attached to the cover.
https://www.youtube.com/watch?v=zaoUMLz8vBcAlso, here is an article on the mod most clocks need to get them running again. This is on the MBCA website at:
http://mbca.org/sites/default/files/7008874_Clockrepair2.jpgBut it no longer includes the pictures. The following is a copy of article with the pictures as well although pictures are black and white and a little hard to see but I think this is the best you can get. The procedure was written by James Mahaffey, a well known nuclear engineering expert from Georgia Tech, whose hobbies include these clocks and old Becker radios.
http://www.benzworld.org/forums/r-c107-sl-slc-class/1545131-1972-vdo-kienzle-clock.htmlIf you are doing the mod described in this article and the youtube video, the person in the video keeps talking about a zener diode but it really just a plain old diode. Amazon has them for practically nothing but the shipping may cost more than the diode. If you are in the USA and there is still a Radio Shack around, they usually have a diode close enough to do.
My clock had not worked in about 30 years and this mod was all it took to get it going again.