Hi Michael
A bit late but found your forum note on rope knurls.
AccuTrak in the States make them and their UK agent is
ATM Machine Tools
Unit 4 Molly Millar's Bridge, Wokingham RG41 2WY
+44(0)118 977 0099
They are very expensive ~ GBP200 each.
I have been making various 'old style' Morse keys and have used the knurl on the screws.
I made a knurl using ClickSpring's video and it worked but it was not fine enough for instrument type terminals.
Kind regards
Alan