Any old Schwinn experts in here?

[Spectaculiciousnes]

I recently "restored" an old Schwinn Twinn tandem that's been in my family since I was a little kid (almost 40 years). According to a Schwinn site I found, the serial number (DA31965) can be traced to the exact day it was manufactured. Which according to the number on the frame & what this site says is April 14th 1965. The D is for April & the A signifies 1965. I also find it quite interesting that the last 4 digits are in fact 1965 even though these are supposed to have nothing to do with the production date. I think that's just a strange coincidence. But that same site says twins weren't made until 1968 so why do the number say it's a 65? I'm baffled. Anyone have any ideas on this discrepancy?
Here're a couple pics of it now & a pic of the number before I painted the frame

[gearhead94]

Very nice job on the restoration. Looks raeally fun to ride around.

[Spectaculiciousnes]

Thanks. It's a blast to cruise on. The 39" ape hangers are actually more comfortable to use than the stock bars were. It's a perfect riding position right now.