Here I just part those out here too. Too time consuming for what the customer are will to pay for. Here by the time those need major parts the parts cost more than new replacement equipment as the rest of the equipment is usually pretty well worn out too.
By all means if you replace the tins transfer the old numbers to the new tins. It really frustrating to receive an engine where someone have changed out the tins and you get one with the wrong numbers or no numbers at all. When this happens we end up falling back on our experience and our ability to do puzzles.