Tascam 112 122 and others set scew for silver Knob pack of 4

I have been asked many times for the really odd sized set screw/grub screw for these Tascam Cassette  recorders as very dificult to find, pack of 4.

THIS LISTING IS FOR THE SCREWS ONLY THE KNOB IS NOT FOR SALE JUST SHOWN TO ILLUSTRATE THE TYPE OF KNOB THESE GO INTO