That's true, if you are replacing the front mount on a beam pan, which I did, too, I would agree that it would have been easier to have it on a frame rack. I bought a complete headset and welded it in, but I must have spent well over an hour getting everything as true as I could before firing up the welder - a true PITA!
He has a useable Super Beetle pan, though, and a CMC conversion kit which bolts up to the SB suspension points (Struts, A-arms and shock mounts) and that accepts the new beam. It should be as true in alignment as the original SB was, I would think. It certainly is rugged - IIRC the conversion kit was made from 1/4" steel plate with rectangular tubing welded on as mounts!