Hey, Rob,
 
I have quite a bit of material I've collected over the years on the  
subject, both for archaeological sites and extant structures.  I also  completed 
the excavation of the Mount Clare greenhouse and wrote the final  report a 
number of years ago.  When I get back into the office after T-day,  I will 
send you some sources.
 
Cheers,
Dennis Pogue