A833 synchro question

I have a torque lock style synchronizer assembly which I think was only available on later OD transmissions. They use a special hub but the keys are the same as for the other 1970 and later synchros (3/8" wide) - at least that's what I thought. The cutout in the slider sleeve is very shallow and the keys slightly rock (meaning the bump on the keys doesn't fully seat in the cutout).
What am I missing? Do I have the wrong keys? or does it even matter that the keys won't fully seat in the cutout?

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I'm using the wider keys (narrow ones are 67-69 keys).

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Is this hub still useable? Shall I try to file the sides a bit?

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