Bruce, you are thinking of the M26 and M26A1 Pacific tank transporters. The M26 was armored, and the M26A1 had an open cab similar to this Kenworth 580. The Pacific was much more massive with a Hall Scott 400 engine and a Knuckey dual chain drive bogie. The KW 580 had a Hercules HXD and conventional Timken rear bogies. It had Holmes wrecker equipment.
M26 Armored cab owned by Frank Buck.
M26A1 also owned by Frank Buck