TR3 Control Head

[Robert Dowdy <ABCDOWDY-METU@worldnet.att.net>]

Does anyone on the list have expanded view of the Control Head, I have
taken mine apart and in order to replace the wire harness, there is a
screw behind the horn push button opposite the signal switch which
doesn't seem to catch on and threads, have I possibly lost a small nut.
Thank for any help.