I don’t have the room and never used one. But I learned so much when I ran onto a deal on a good stereo microscope. Wanna know why a tool doesn’t cut good? Wanna know which direction grinds better with a smooth edge? A lupe helps and jeweler visors really help, but a microscope really is the final word. I can only think a comparator has got to be even better. They come up often in LA and SF, but never that cheap and in the case of the Lufkin, in that nice of shape. Although I have no idea what it would take to get the light working for all I know it could be really expensive.