old motors w/ encoders

I have a number of 16v dc motors with encoders on one end. The
brand is Hathaway & dated 1983. Are these to old (induction motors)?
could they be servo motors w/encoders?
Hathaway still makes encoders but no info on these old motors. To
cheep to throw them away & still looking for a use for them.Anyone
used any old Hathaway motor to a good end?
Thanks Dennis