ID: Inside Diameter - OD: Outside Diameter - L: Length
39 is the inner spacer, 13mm ID, 18mm OD, 162mm L
37 is the sprocket side spacer, 12mm ID, 22mm OD, 11mm L
45 is the brake side spacer, 12mm ID, 22mm OD, 18mm L
I'm guessing the 12mm spec is a misprint because they have to slide onto the 12mm axle.
To simplify things, just get some steel tubing that slides over the axle without excessive slop. The tubing needs to contact the inner bearing race and nothing else. Cut it to length with the ends as square as possible, a lathe is ideal for the job but you can get by with an angle grinder if you wrap tape around the tubing for a guide and cut carefully.