provided the complete kit, which included the bolts, nuts and a generous supply of galvanized washers. The mounting and backing plates were galvanized by 3 Bros. - they don't come from the supplier this way. A very nice consideration by 3 Bros..
The only issues during assembly: the galvanizing of the chassis had made the bolt holes too small by a small fraction, and had to be drilled out. A larger problem was that the holes of the mounting plate and those of the chassis didn't line up - the top right was out of position. This had to be corrected for the bolt to go through.
Below, the kit, with tow ball masked off in preparation for priming and painting. The ball/pin casting is zinc plated.
Just a view of the casting with self-etch primer so the paint will adhere to the zinc, and after painting.
On the left, the original pin-only fitting (welded to mounting plate, in turn welded to rear cross member when the previous owners made their own replacement cross member).
The Workshop Manual illustrations (supplied by 3 Bros.) for attaching the tow assembly. While the double-nut method worked well for the smaller upper bolts, it wasn't possible for the lower, due to the flange on the rear cross member (see next photo).
The thick backing plate has to be placed in location first (to prevent pull-through of the bolts when under load), then the nuts, and then the bolts put through from the outside. There isn't room for lock washers. A check for tightness will be needed now and then. The hitch bolts will need to be longer if double nuts are to be used.
The final assembly.
