If by "fixing" you mean taking care of deferred maintenance, fixing squawks, etc then yes absolutely. Any buyer is going to ask you to do that stuff anyway.
If by "fix" you mean new paint, new interior, new engines, then no, you will never get your money out of those sort of things.
Your airplane is somewhat unusual in that there can't be many, or any, one-owner Turbo Commanders left (maybe the State of Montana with their 680V?), although whether or not that adds value, I couldn't say. It would add value to me, but I'm not in the market at the moment.