My suggestion, leave alone and just use
Pulled out my Brand 4X5 to refresh the memory, I am not a writer but will give instructions.
Remove lens board. Just inside of lens board area are 8 screws around opening. One in each corner and one along each side. These screws go into a board, wooden in my case, so these are wood screws. Remove screws and front bellows will come free, may be stuck in place from old glue and such, if not just habit from years of being connected.
Fore the rear, remove ground glass. Loosen thumb screws that keep glass assembly in place and from rotating. Again look at corners wood screw in each corner. Wood screw in recessed area you can not see until ground glass assembly is removed. 8 screws.
By now bellows will be free to be removed. My suggestion if you want to paint and keep the look use "wrinkle paint". Popular with the automotive crowd. You will have to do the research.
back to my first suggestion, just use it. wait till you need to replace bellows and then make a restoration / modification project of it.
This is a beast of a camera and a better man than me would use this hand held. I wonder how but I understand it was done. I do not think a camera like this could even be built and sold today, The moulds for casting the body would cost a small fortune. Take care of it, will last the rest of your life.
Good luck
Aj