I don't know the answer to K. Doesn't matter too much so don't sweat it for now.

But...F is a serious problem. If you're getting more than 2" difference in a comparative cross measurement, this explains why your rear end is installed crooked and one wheel is sitting forward. That is WAAAAY out of square. Not good. Your G, J and I measurement variations are substantial too, and what you report seems to indicate that this car has some issues with the placement or shape of the rear frame rails. It seems one rear frame rail is a full inch shorter than the other? Possibly wrecked (rear-ended right rear corner most likely....pretty hard, and poorly straightened) or maybe replaced fully or partially due to rust repair and improperly located?

Hate to bear bad news but I'm not very good at sugarcoating things...so my apologies in advance. But your car has some issues here that are not easy to fix. Are you prepared and capable of handling a possible full rear frame rail replacement? If no, you might want to get this car over to a good frame/body shop and get some input from them, see what they feel is bent/misplaced and if maybe it can be straightened or relatively easily repaired somehow.

Unibody/frame repair is sometimes LESS expensive than you think with modern frame pulling equipment. But if someone has already welded on a new rear body panel and quarter panel, while the floor/frame rails were not in the correct position, it may not be possible to repair the unibody without destroying all body lines and gaps in the process.

I believe you'll never get this car to track straight with numbers like that, and it needs some structural repairs.