never saw a portable,doubt if there was one because i would think the center would have to be massive and well supported, because the ride is out of balance.The centers on the park units ar a large hunk of cement who knows how deep in the ground. there is one at kennywood, one at Coneaut lake and there was one at Whalom park before it closed. i believe thats all thats left. i think kneobles bought some rides from whalom, hopefully they bought the Bug and plan to restore it.
maybee flamo, pinetar or rrshow can help