The hoods, which resemble the face shield of a suit of armor, took the longest to clean - almost 20 minutes each - and wore out three sanding sleeves because of deposits of creosote, which had dripped from the walkway of the signal bridge when it was parged, on two of them.
Next were the plates that protect the wires going into the lamp unit - small T-shaped pieces that took about 15 seconds each to clean up. Then it was time to tackle the "bezel rings" - large pieces of metal, shaped sort of pie pans with handles on the back, to which everything else is attached. The odd angles and the lips/ridges on these made them difficult to sand with machinery - I had to do most of the sanding by hand.
Before I did the bezel rings, however, I decided to get the small things out of the way: dozens of screws, washers, nuts and knobs. They all needed to be cleaned up - some were so bad the metal was pitted - and they all had to be done by hand. Fortunately my wife got me a toy that I asked for for Christmas - a 300 series Dremel rotary tool. I went out and got a flex shaft attachment, and the task cleaning dozens of small pieces went from a nightmare to two nights of ease (well, easier than sheets and sheets of 220-grit sandpaper, untold nights at the workbench, and cramped fingers...).