Oh wow! Thanks for posting this. My '37 has the old-school Mustang II crossmember, too. It drives just fine (at least it did before I tore it down for a rebuild...:whacked:) but it's not very pretty. I've debated on whether I wanna cut it out and start over. This process is definitely food for thought.
Of course, with all the other work my chassis needs to be show quality (not that I really want "show quality"), I'd probably be money ahead just to buy a new one
35 40 Ford Chassis Rat Rod Rat Rods Ford Other New Frame Custom | eBay