this is a custom inspired piece for under the vhook.
the movies used just a rough cut piece of scrap metal and put it under the vhook to support it(reference picture above, thanks to Vince).
we did not like the look of scrap metal, so we designed this disc inspired by the track disc to give a much nicer look.
the back one should be supported also but can be done so by a 1/4th thick nut or some stacked washers, as the back one is never seen from any angle.