Naturally the first step in refurbing anything is cleaning it.  I began, as you can see by the center photo, above, by disassembling the entire signal down its its basic components.  Unlike the first lamp unit I refurbished, this time I had a drill press and a set of drum sanders; trust me when I say this sped up the process significantly. As shown in the following pictures, I used the drum sanders to remove rust and old paint from each wire cover, back plate, nut and spring.  I also figured out, while sanding the wire covers, that metal being sanded at high speeds gets very hot very quickly, and that wearing heavy gloves during this entire process is a good idea.  Unfortunately I managed to burn myself and sand off part of the fingerprint on my left middle finger before I came to this realization.

Duh...!

Wire covers, before and after sanding	23 of 24 nuts are brass; one is steel.  The nut on the left has years of coal smoke and diesel exhaust caked on it; the other two nuts have been cleaned.
Spring cleaning (no pun intended)	Back plates that prevent outside light sources from creating false indications.

The springs were tricky; I ended up chasing the first few all over my shop when they worked their way free from my grip.  I finally figured, as shown in the third photo (immediately above) that if I held the spring against the sanding drum cupped in the fingers of, and seated on the heel of, my right hand, and secured it with my left thumb, the spring would rotate against the drum in a counterwise rotation and would be cleaned very quickly.

The nuts were pretty straightforward, but there are indentations around the top which I had to clean out with a piece of fine grit sandpaper folded once to form a sharp crease that would fit into the grooves.  I still missed a litle, but the nuts look a heck of a lot better than they did before I started.

Next were the outer lens retaining rings.  Also done on my drill press/sanding drum setup, it took about 30 minutes to do all eight rings.  However, the condition of one of the rings is so bad that the metal has completely corroded away at some points (when I first saw it, I thought it was merely blistered paint) exposing the rubber gasget beneath (see pictures below).

Outer lens retaining rings, before and after sanding	This ring is so old it has corroded to the point that the rubber gasket is exposed.
Severe pitting of the remaining metal of the corroded ring.	Refurbing is dirty business.

Several of the rings are in seemingly almost-new shape and cleaned up very nicely; others, however, show their age with heavy pitting.  Either way, they're ready for repainting.

[The photograph of the two masks indicates just how dirty a job refurbing can be: the mask on the left is brand new; the mask on the right was worn only to clean the eight outer retaining rings.]

Next are the shades.  These should be interesting...they're huge, in surface area, compared to what I've done thus far.