430 Mystery part?

Anyone recognize this piece of hardware? It looks like a bushing of some sort. It isn't threaded, but a bolt goes through it (can see shadows of threads).

I found it on top of the front of my gearbox, right over the input shaft.

TIA.

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Sorry for lacking dimensions. It is pretty small.

The "flange" part is 18mm across, and the through hole is for a 6mm bolt. The height is 11mm.

 

Thanks for the info!

The starter and alternator bushings are larger, and I can see that the starter bushings are in place.

My car is a converted manual, so I'm leaning towards #25 in the second pic. Possibly it was a part left behind that found its way loose?

I just can't figure out how it would have landed where it did. I had the transmission completely out to change the clutch 7-8 months ago, so I know it wasn't there when it went back together. Also did cam cover gaskets, cam variators, refinish of the intake and cam covers at the same time, among other things.