jim haseltine
Senior Retro Guru
ISTR that we had 3 boards. A blue one (Maillard) and a white one (Suntour) in the shop and another on a wall in the workshop with Regina Extra and Oro on it.I remember at one point most decent bike shops had these massive boards with all sorts of Maillard cogs to build anything custom and replace anything worn.
Availability (or lack of) of replacement cogs for cassettes is yet another thing that bugs me these days. I spend a good 75% of my time riding the same cog (and I suspect most other people do the same) but when wear rears it's head I've either got to hunt to find the part I need or fit an entire new cassette.