Herman,
Actually, I saw two cubs today that sound quite similar to the one you have. They were both 1969 models. One was 20# the other 49#. You might be able to date your bow by the serial # also. If your bow was manufactured between 65-69 the first digit of the serial number will be the year of your bow. Such as 9Cxxx for a 1969. A 8Cxxx would be a 1968.
My cousin owns the 20# Cub and the 49# we saw at a trade show that we attended today together. The owner was asking $70 for it.