If I drilled the top starter bolt through it would pass right through one of the pivot bolt holes. The shape on the backside doesn't look compatible with a bolt hole and no way to get in there to grind it flat either. So that's a no-go.
If it doesn't hit on the block or other parts it will bolt right onto any Mopar then, so you weren't wrong to think it would fit an LA or RB.
I'm going to take the starter I've got with me to see if there is anything different on the shelf in a mini-starter that I don't have to use a drill to make it work.