I need a replacement for my Shimano 333 trigger shifter, which has been breaking - and is now broken. This is not the first time I've needed a replacement for this type of shifter. Does anyone know if an old SIS 3 speed trigger shifter might work? Can 333 and Sturmey be used to replace one another? I have plenty of basic friction thumb shifters to use in the mean time, but wondered if there was something with 3 clicks that would work easily in the future. Sorry if this question is stupid. I swear.