DeirdriuC
Dee,
Yours was built in November 1973, and it has the 3-wire cord on it.
I see you are looking for a replacement outer bag for this machine. At the time, it was part no. 3-060642-201, but Royal produced these in different colors over the years: gray and orange bags are easier to find these days than these old blue ones.
What specific information, besides the outer bag, would you like to know about this machine, please?
~Ben