Help fixing chuffing Annie

Lol that sounds an annoyance I know as well especially since these parts aren't very expensive I wind up eating the costs if they're wrong. (Also, often I don't need 25-50 pcs). Yes 2 they are 2mm because the one shaft as DuckGWR stated is 2mm thick but the 24 tooth which has it's own plastic axle as part of the gear, was measured at 2.5mm but the diameter is still 13 and the guessed diameter for the 16-20 tooth was 8mm. My listing for the 16T is 9 so I thought to try that one. I'm just waiting to see if anyone has better sources before pulling the devil trigger; perhaps even the 12 tooth with the axle built in because that's going to be a pain in my... Rear buffer to create a makeshift axle between it.