i made a bunch of these sleeves/collars [whatever you want to call them] many years ago. very simple to make, .002 press fit, and the diameter and length are not critical dimensions as there is lots of room around them after installation. just get a chunk of 1 3/8" [1.375] diameter mild steel bar stock and start cutting. bore the inside diameter to size for a few inches depth, then cut off your needed amount of collars. rinse and repeat if you need more. no need to turn the od if you start with 1 3/8" stock.