Impressive!
I've got a garage in similarly wretched condition that I was going to ask about teardown VS refurb...but you've convinced me I can get the job done and keep this one (and my finances) alive.
My only comlication to re-doing the floor is that I've got support posts down the middle...
That would Los Angeles.
I've got a hovel of a shanty of a shack of a garage that I'm trying to figure out what to do with, along with a relatively large driveway in need or repaving.
I'll have some questions in the general forum, along with some quickie writeups on some stuff I'm working on.