I think that both you and the shop owner should have had a real serious meeting of the minds about this job before even starting it.
They’re 9 hours in and haven’t even gotten things apart yet?
A going on 22 year old car with lines rusted that badly could also mean weak brake hydraulics such as calipers, wheel cylinders, and master cylinder. Replace the lines, some of the hydraulics may then give out and then what?
You may have more in the repair than the car is worth.