On the wishbone clip you may not need to get a new one. If you remove the old one and squeeze the head of the clip together this will increase the tension of the clip in the slot on the gear. This will fix the issue yu have.
I thought I had a pic shopwing where to squeeze. Ican't find it. I recently upgraded to windows 10.
After you squeeze the clip and reinstall it on the gear you can test it by holding the shaft and hooking a spring scale to the head of the cliup and turn the clip on the gear. It should take at least 5 lbs. of pull to move the clip. If you don't have a scale to use you can tie a string to the clip and the other end to a gallon jug. Put 5 pints of watyer inthe jug. This equals 5 lbs. Lift up on the shaft and the clip should hold up the jug. If not squeeze the clip tighter.
In 74 I think was they changed the clip. They made it outof heavier wire and the head of the clip won't fit into the notch in the case. If you usev one of these heavier clips you need to set the head beside the notch.
Leo