Great work on the car and the video
I know where you are coming from with having your own garage to work on the car and leave it in bits and not having to worry about weather etc especially doing bigger jobs in this climate. My car spends more time on axle stands than on the ground
You could always try the Por-15 products for the underside of the car, they seem to get good reviews and should give a really durable finish, I have seen people applying por15 with a brush which can help make it easy to apply without having to cover too much up. I ended up painting the whole interior and cage on my car with gloss grey boat and bardge paint using a brush and the finish is very good
Keep the updates coming