Thanks Roy. Wasp's hull is 63" and she currently measures 77" overall, almost 2 metres. She was originally yawl rigged, and dates from about 1900, if not a little earlier. I am seeking information from the US Vintage Model yacht Group, and researching assiduously, but there seems to be very little known about the many "steampunkish" steering devices developed in the decade or so prior to Braine Gear in 1904, to quote the Central Park Model yacht Club website. An article written in 1902 describes an "up-to-date" quadrant design described as far superior to the "old screw gauge"--which is what I think Wasp has. Her tiller can be screwed down to clamp it at 11 different angles or released to work against a centering elastic. Attached photos show the current tensioning fitting, which is a later addition, and the circular marks on the deck beneath it with the fitting removed.
Photos on te internet have not helped me at all. They are mostly Braine gear or vane gear, or damage and/or incorrectly rigged! Thanks.