Doug,
I am in the process of trying to pack up his kits right now so they can make the trip to Cincinatti. The grand opening for the museum is coming up soon, and I hope to get the boxes there before it is too late. It would probably take two or three hours to itemize all the little pieces and tools.
I like to fly fish, as most people know. I relate Steven's kits to my fishing vest. You start out lean and mean, with just what you need to fish an afternoon. Then one day, you get caught in a cold winter storm, and realize it would be a good idea to include a cheap plastic poncho and a NASA style aluminum blanket. Waterproof matches also sound good. A compass? Not long afterwards, I added a whistle to signal a downstream fisherman, or send SOS signals if I got in trouble. One day I fished until dark, but the fish were still surfacing, so I added a small flashlight to see the fly as I tied it on, and also to see the path on the way out. I dropped my hemostat pliers into the river one trip, so I now carry a spare. Same for tippets and leaders, plus lots of flies for about any occasion. I also carry a Slim-Jim jerkey stick, and usually carry a water flask, along with bear spray when in certain parts of the country. So, before long, I have the heaviest vest of all my fishing friends. It didn't start out that way, but grew as each circumstance arose.
When I look at Steven's kit, I see much of the same little additions. At some point, he needed some string, some fine chalk, numerous pens and markers, scrapers and cutters. Pliers for opening the lids, can openers, magnifying glass, mirrors, tripods, lights, tape, scissors, sharpeners, wrags, cans, compass, levels, and numerous measuring devices. Each of those goodies were probably added to the ever growing sign kit boxes. In the end, most of what is in the kit seems very logical it would be there. When I trek across a meadow to a stream, I know I will be gone for several hours, so I try to plan on having everything I might need with me. When Steven went out on a bank job, he knew he would not be able to run home to grab a couple of new stabillos. Many jobs were in very small towns, with no Wal-Mart to fall back on. He often worked late into the night on a project, so he better have the supplies and tools with him.
With all that said, Steven Parrish was a bit of a showman. I'd say about two thirds of the brushes in that brush kit were basically useless. They were clean, but many were harden at the ferrule. Many were the same size and duplicated. Considering the type of work he did, most of them were much bigger than the brushes he would use on the job. Still, it would be an impressive site to walk by the open box and see all the "necessary" brushes.

One jig can be seen in the photo above. I think there are a couple of different size jigs in the compartment. Each had two little telescoping outriggers that pulled out and were tightened with a couple of alan set screws. He adjusted the outriggers to be just a tiny bit too long, then wedged it between the door frame. He could adjust the screen placement by tapping it a little as necessary, until the point he taped the screen to the window. There wasn't too much more to the jig you can't see in the photo, except for knowing about the set screws.