This seems a good idea and I see the supplier has a spanner version ($2) and a round type ($11). In my experience, I would suggest certainly having the more heavy duty round type as some Sifam knob collets can be very hard to undo, especially on Japanese consoles as they run hotter and there could be a long term chemical reaction or binding between the brass nut in the knob and the steel shaft of the pot.
Sometimes, I have had to put a lot of downward pressure on the SSL round tool version in order to undo the internal brass knob collet nut so the spanner may not work so well in these circumstances and could wear out quicker.
If you do a group buy, perhaps you could have various purchases per Country to save dispatch costs all over the world. If the supplier knows that they can sell a larger quantity to several Countries in one go, they may be more inclined to offer a discount overall.
Just my thoughts and good luck with this from Jim Lassen in the UK
