Sure looks like a dark green cs grade otca to me... And a pretty one. I think the original number was correct. Seems like most Old Town serials didn't start with a letter...
Welcome to the forums, btw. Don't know if you're still in the Minneapolis area, but the Minnesota chapter is planning an informal paddle on Lake Nokomis later in May (the 22nd, I think?) I'm sure you'd be more than welcome to attend.