Dan has the right idea. That ebay seller is great. A year or two ago I sent him the mirrors from my Rolleicord and Voigtlander Focusing Brillant TLR, and he cut the mirrors that he sells directly from those as a guide, so they fit perfectly. He's a nice guy too, w/ excellent prices. The Rolleicord mirrors are a snap to replace, w/ just a thin metal, Y shaped copper colored thingie that goes behind the mirror to help hold it in place. Take out the 4 screws that hold the waistlevel finder on top of the camera, lift it straight up and off, and you'll see right away how to take the mirror out and replace it. You shouldn't have to readjust the focus or anything. There COULD be a shim or two under the WLF, but just put it back when you put the WLF back on. The Voigtlander TLR mirrors are even easier.