Yup, feed rail work maybe needed.
Cory, I have done 15 or so Mauser conversions and you will not get the money you invested out of it if you decide to sell. Your better off just replacing the stock and call it good. Boyd's gun stocks has Mauser 98 stock unfinished for $75.
For a build I would look at the Savage 110 action, or the Rem 700.