Thats cool that you got a 4X5 enlarger. I recently bought a Crown Graphic camera and an Omega DII Enlarger. The enlarger was $75. It has a Bausch and Lomb f4.5 139mm lens. The problem was the lens was frozen at f11. The fix required some carburetor cleaner and a large pair of pliers. f-stop ring is very smooth now.
Nice 'All American' setup there. Some Kodak film and you are ready for Memorial Day.