I wouldn't want to try to explain it until I can see it again ... but your
> post may be the impetus to do that at some point this week, as I've got a
> project on burner that I may want to use the idea on.
Earlier in the week I contacted the fine folks who run the historic building, and this morning they were gracious in allowing me all the time I needed to photograph the wooden drawer slide method previously mentioned in this thread:
It is even simpler than I remembered, but very effective.