Nice run Jim ... I enjoyed seeing that realizing what an uncommon sight that is as well!
The reason you rarely see vacuum engines running accessories is due to their inherent lack of power based on the fact that they are operating on something substantially less than 14 psi. Seeing as they are often quite temperamental, and having little power, most any load is likely to be something of a problem for them. So you getting that one to pull the table saw was good!
I once got my Solar Engines #3 to run my Jensen #100 workshop, but it took a lot of fiddling and false starts to manage it, and I wouldn't bet any real money that I could do it again on any given try.