Thanks for your reply and identifying the shortcomings.
He was originally planning to patch up the floor panels to reduce costs. I have specifically instructed him to cut the old metal out completely and replace with new panels. This will be done once outer work is completed.
He also said that the welding job is not final yet. The panels are just attached to the car for now and will be properly welded and ground to blend into the body before preparation for painting.
A new roof has been sourced and will be fitted once doors are attached. Currently, he is evaluating if any of the existing doors are salvageable. I have anyway given him the approval to buy all four doors and not worry about putting rusted stuff back in,
Now that the project is properly underway I am beginning to question my decision of picking the body-shop hastily. I know he is cutting corners, which is why he was also the cheapest option available. I picked him because of close proximity so that a close eye can be kept. Let's see how things go.