I have looked at several websites and I cannot find a match based on what I think this code reads. Anyone have an idea what year this thing is?
date code by individual image, on Flickr
_MG_0263 by individual image, on Flickr

Serial Numbers

Before 1965 serial numbers were stamped onto a rear dropout. Beginning in 1965 serial numbers were moved to the head tube and the following date system was used for all Schwinns except Paramounts. The letter at the beginning of the serial number indicates the month of manufacture, skipping the letter "I." For example, "A" = January, "B" = February, and "J" = September. The second letter of the serial number indicates the year of manufacture (not the model year), beginning with "A" = 1965. Skip the letter I & O. Sports Tourer KH017873, for example, was built in October 1972.
For more on Schwinn serial numbers, check out the Waterford site.

You probably ran across this already. I don't know if it will help.

The serial numbers were on the rear dropout from 1952 up to sometime in early to mid 1970. They were moved to the headtube in 1970 until the Chicago plant closed.

Your S/N appears to be BC**** which would be February 1967.

There will be additional date codes on the cranks, stem, and possibly the hubs.

BC03421 = old

I think this is most likely because of the seats. 1967 it is.

Thanks