I have had a few Sherzer Piccolos through my repair shop recently and have been very unhappy with their valve action. To be more accurate, dissatisfied with the linkage; the very old system which you can adjust the free play (rattle) by tightening a screw - until the whole action locks!
When I was designing my Jaegerhorn (rotary valve, vertical bell corno da caccia or posthorn), the original cluster had this outdated action so I visited Martin Seibold in Bavaria and had a set of Minibal linkages made up. The difference was chalk and cheese! An ordinary valve action was transformed into being silky smooth and lightning fast.
Surely there are some Scherzer players out there who would like this mod? Or players of any other Rotary trumpets/flugels/etc? I can fit Minibal linkages to all of these.