its doubtful you will find the father of Harvey, perhaps he never knew himself, there would only be a few people who knew this information, the mother perhaps the reputed father, and maybe Grandma,
I think perhaps you will have to settle for just knowing Jane was his mother, if Harvey himself had married and had children DNA would have been a way of finding out the truth,
good luck with the rest of your research, Harveys death is well recorded ,sadly his baptism I can not find, that may be accessible in the local archives in Canterbury , Methodist or non conformist records ,