I have an older zeiss scope with the inner rail built into it. I'd like to mount this scope to an Interarms(Zastava) rifle which has a two piece Picattinny base installed.Is there such a thing in existence?

They are available.

http://swfa.com/Zeiss-Railmount-P10782.aspx

Thanks for the link. It's a bit pricey but seems to be the only option I have.