if it is rusty and rotten then noting.
i see that you are new here. am sure you have read some things on the forum. your question is like what is the price of a maurti 800?
without pics description etc the the price of maruti 800 is only junk value.
so if you want an good response then do send pics and other info, ie bore condition etc even better why not take it to a dealer and see what he say then add !0%
if you say it can not be done, then you are right, for you, it can not be done.