There is a wealth of information to these prints in the basement of the old building. Study them long enough and you get a sense of history passing by, a genealogy of sorts, or archaology. I've mentioned them to a former painting collegue, who's now working for an architectural firm, that he could come look them over some time, as the owner has given me the priviledge. He must be too busy.
[Addendum March 17, 2008 - for use in estimating safety lines and cordons:]
After inverting the colors I can get a basic idea with MS Paint on where I want to string main safety cables to drop down the roof from.