Hey Scott
this is really looking the goods!
One query though. Where you said in review about the down(drain)pipes. You were going to use a 'Y' section to have a branch to a barrel which I assume would be at the base of your building; was this researched off actual plumbing of the time, or of your own choice?
In my own plumbing experience this would not be the place an O.B. or 45 degree junction (the 'Y' section) would be present. Granted you wouldn't see it nowadays, but I'm assuming (only) that the plumbing of the time would be of the same thinking. I merely bring this up for accuracys' sake, but if, as I said, you had seen this then

button my cakehole :-)