Bret,
I have not seen the equipment displayed at Stevenson, but I can make a few comments based on what I know of such equipment. Steam "donkeys" came in quite small to pretty large sizes, the nomenclature applied more to the type of work they did. Donkeys generally had a spool (capstan) or 1 to 3 drums, and were used for ground lead or simple high lead yarding. A separate engine was used for loading, or sometimes the locomotive itself was used. The large machines used on inclines were also called donkeys. When more drums were added for skyline yarding the machines became known as skidders, and often the loading and rig-up engines were incorporated in the same machine. These grew to huge proportions, up to 400 tons, which strained the carrying capacity of the logging spurs.
You are likely correct about the Cat 10, the smallest cats used in the woods were generally Cat 30's. These were often used as "break out" cats to position the logs so the skid cat, usually a 60, could quickly pick up a turn. I would think that the size of the timber in the Stevenson area would preclude the use of cats for logging however.
The mill boiler front may not be from Dee. The first OLC mill in that area was Mill A located near Cook, between Stevenson and White Salmon. I believe that mill burned fairly early, after which the logs from that area were rafted to Hood River. There was a railroad into the woods from Mill A, powered by a 0-4-0 dummy from the Ogden street railways.
Lastly, when I was in the woods the "rigging slinger" was the guy who picked which logs to make up into a turn, and who untangled the rigging when it got to where the turn was to be choked. The guy who rigged the spar tree was called the "high rigger" or simply the "climber". These terms were generally used industry wide, but some outfits may have had their own nomenclature.
I have not been to Stevenson for many years, I guess I will have to make a trip.
Jim
