Seat mounting assembly for Ariel Model A 1929

[Alan.Rogers]

My 1929 Model has the single post seat mount with a tilt bracket on the seat to set the angle. This bracket is all present, but is worn in the grooves which set and lock it in place. Has any body devised a method to lock this swivel bracket to a particular spot, as a permanent and locked position?
Any info appreciated, Thanks, Alan