Good news,
I have the above image of the original plans in a .pdf file. I took it to my local blueprint copier and he printed it out and was able to enlarge it using the scale drawn on the plan. He got it to within 1/32". Close enough for a Stik!
If anybody would like the .pdf file let me know and I can e-mail it to you.
Grid Leaks Plan Service is long out of business so I don't know any other way to get an original copy.