Thanks for having a look at the picture I posted and following up with additional recommendations. Breaking out the side of a receiver would be a catastrophe and potentially dangerous with a sudden release of energy and I should have included the fact that this would work in a pinch or at least in a situation that would not require additional means of substantial leverage.

The tool that I made is probably not the best to select to use for all circumstances but up to this point I have not encountered a condition that would require the application of a cheater for the extra leverage. The original intent of the lug was to try and distribute leverage in a way that it is partially distributed inside and at an angle to the radius of the receiver.
In other words if the receiver was visualized standing strait up on the tang, some but not all of the leverage would be at 4 and seven o'clock. or at least enough to avoid the risk of damage. Maybe the pictures do not accurately depict the contact but it does occur to some extent.
I would imagine a picture of an arsenal tool that was originally used would be available  but I could not locate anything to get a better idea to put something together that would at least work.