Well, if you've got about 3-4 feet of steel tube of reasonable size (you have to support approximately one and a half times half the weight of an MGBGT plus a reasonable factor of safety), a left and right handed heim joint and left and right handed nut, a block of steel maybe 4" by 5" by 1", a few feet of 1" by 1" Angle iron and some heavy gauge sheet metal, you're all set.