Buggy Shafts

I bought a buggy that needs serious help. The under carriage and wheels are in good shape. I am going to rebuild it into a buckboard wagon. As of now it has what appears to be fiberglass shafts on it. I was wondering if anyone has ever made shafts out of black sch 40 pipe? A new set of shafts from the local buggy shops will be more then I paid for the whole thing. So I am thinking about making my own. I am pretty new to this all though. Can the pipes just be straight or do they need that curve in them that most have? Any help would be appreciated. Also what is the standard draft size demensions. Thanks.