Unless you just have to have that particular rod, you're probably better off getting another one. If you must have that rod, don't risk doing it yourself to save a buck. We usually screw up the first time we try new things like that. Pay someone to do it for you. Someone who does good work. Rodbuilding is a craft, and like other things, some craftsmen are better than others. The good ones are worth the high prices they charge.
I knew a man who repaired and built rods (he wasn't that good). From the little that I was around him, I think it would cost the same to have a rodbuilder start with a brand new glass blank (like the one you have now) instead of having to pay for the time and labor of refinishing your old one. Unless the old one has some type of sentimental value, I'd go with a new one that I could customize (reinforced ferrule, type of guides, tape color, etc.).
There's some skilled rodbuilders around here who could give a more definite answer. I'd like to know: Would it cost less to start over, or refinish an old rod?