Correct me if I'm wrong, but this is not a Sanger. Hull design is close, but wrong, HIN shows a handmade boat out of Illinios. Doesn't fit the T-bubbledeck style in '85.
http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA:IT&ih=007
Judging from the depth of the runners, I would agree with you. Also, I just bought a 74 bubbledeck and the HIN starts with SAN same is true on my 84 Hydro. I don't know just my 2cents worth anyhow.