Look at the third gear: http://home.nc.rr.com/ericandjan/bad.jpg in this '74 four-speed gear cluster.
It goes onto the shaft just fine, it engages the 3/4 slider and the synchros just fine, it's exactly the right diameter and thickness, which explains how I managed to reassemble the cluster without noticing that... the teeth are cut backwards ; they run crosswise to the teeth on the other three gears. So what IS this gear? Not an X1/9 four-speed third gear, it seems...
It goes onto the shaft just fine, it engages the 3/4 slider and the synchros just fine, it's exactly the right diameter and thickness, which explains how I managed to reassemble the cluster without noticing that... the teeth are cut backwards ; they run crosswise to the teeth on the other three gears. So what IS this gear? Not an X1/9 four-speed third gear, it seems...