As Boyd surmised, there was never any business connection between Homer and Lyman. If you wanted the conversion, you dealt directly with Homer, giving him a Lyman 55 and getting it back with a powder insert he crafted specifically for the measure you gave him, plus the original insert (I think you could also have him purchase a 55 for you and add his conversion, but we all just gave him a new one we bought), and a table of settings to get you in the ballpark (it was often spot on) for several different powders commonly used in bench rest calibers of the day. Homer specifically stated that a measure with his insert wouldn't throw charges any more precisely than a standard Lyman 55; the beauty of one with his insert was that that it could be quickly, accurately and especially repeatably adjusted to throw different charges with his measure. Once you got the exact setting (at or near the table values he gave you, or developed by you for a powder not covered by the tables) for the lot of powder you were using, returning to that setting for the desired powder weight was simply a matter of setting the micrometer adjustment, without several tweaks and returns to the powder scale. I still have mine and treasure it. Given the number of calibers I was reloading for, with several different powders, his method of rapid, repeatable micrometer adjustment was a real pleasure - until you changed powder lots (and sometimes afterword), just set the micrometer for the desired charge, throw a charge into the scale pan to double check, and you were good to go. My only regret is that I didn't have him build me a second one with a pistol powder insert when he started making them.
