Here is a used Howe Racing steel clamp-on panhard bracket for the 1 3/4" round tubing. Part number 30780.
Howe Racing Enterprises O-Ring - Rubber - Howe Throwout Bearing - Kit
Pair of Vintage Coleman Acro Howe Racing 10 Bolt Rear Racing Hubs w/Plate 5x5 GN
Howe Racing Remote Bleeder Throwout Bearing Brade Stainless -4AN Hose -4AN 8287
Howe Racing 82872 Replacement Throw Out Bearing For P/N 82870/ Bearing Only
Howe Racing 828715 O-Rings New Style Throwout Bearing Kit
Howe Racing 8290 Throw Out Hydraulic Coupler For P/N 8288 Hydraulic Bearing