My fault, should of said i was referring to drag race stuff only as this is what i'm more familiar with, as seamed tube and as far as i'm aware joins in roll bars which should be one piece are allowed.
Drag Racing cage and chassis construction is to SFI plans. You can join tube but only in certain areas. For instance my altereds shoulder hoop is 2 pieces, sleeved,plugged and clam shelled. This is perfectly acceptable in construction and as a repair but there are certain areas ie the cage area where it would not be.
Greatwork on Fred's car BTW, enjoyed reading the buildup on that.