ID'ing an older Serotta

[that guy]

Found this guy on eBay. Can anyone guess at the age/model? I'm confused about the over-the-bottom-bracket cable routing. Haven't seen this on a Serotta before.

Update: SN is 831210

Thanks!

http://img231.imageshack.us/img231/9153/bzoowgbgkkgrhgookimejll.jpg

http://img2.imageshack.us/img2/7677/bzo2cgmkkgrhgookjmejllm.jpg

[Pete Serotta]

old.....probably the early 80s or very late 70s