I'm assuming it doesn't matter which way round the lot goes since you didn't post a pic with the front annotated?

I had the sinking lot thing too. The easiest way to fix it (since it's only an empty lot) is to delete the plants, set CFE false, hit flatten lot then re-size the foundation back to it's original height. It's a lot quicker than faffing about trying to guess the exact number :D

ETA: Remember to move the trash can and mailbox before you flatten the lot or you'll have to dig them out again