Dunne and Hipster001 -- I too have a (Carl) Beetle Gull, so I understand what you are saying with regard to the original hardware for the rudder. Odd setup.
There is some information on the Catboat page (I don't know the link offhand, but can find it). One fellow (name is on file) from "FancyNancy" boatyard fixed up a Beetle Swan and a Beetle Gull. His photos are online. He also wrote up some of the history from the book _Heart of Glass_. When I first got my Gull, I didn't know what it was, but knew that is was a OLDIE. So heavy. DENSE and thick like cast iron.
I was determined to find out what the boat was (I used to "waste time" persusing sailboat sites, ads, and CL). Then I spotted the hull and it was the rehabilitated Gull from the fellow I mentioned above. He is in Georgia, I believe. In restoring his Gull, he swapped out the old rail (track) system and for the conventional pintle and gudgeon set up.
If I recall correctly (but it's online), the boat was made by Carl Beetle around 1959 and was one of the first (not the very first) production glass sailboats. It was apparently baked in the GE ovens (perhaps Pittsfield, MA). Either in the book The Heart of Glass or in the Georgia restorer's narrative, there is a story of how, to convince prospective buyers about the reliability of this new material, C. Beetle fires gunshots into the hull. Sounds like something my father might have done.
Beetle (Fairhaven, MA) was ahead of his time and lost money on his glass boats. His boat company was sold and that company continued to build the wooden Beetle Cats.
My Gull is in need of restoration. It has the centerboard, thwart, and the rudder with hardware. No mast, boom or sail.
I can photograph the rudder track parts and (try to) put them here if anyone is interested.
I think I will part will my Gull as I've got too many boats and projects.
Another odd ball rudder set up is to be found on the Boston Whaler Squall -- another sail-row-motor dinghy. I've got one of those too, but no sail rig (yet). The Squall's rudder has a very long pintle that fits into a sort of "built-in" slot inside the transom. Try reproducing that at home
I've heard that the BW Squall is not so good at sailing, but makes a great tender or lobsterman's dinghy as it is reasonably self-bailing. No Nor'easter, but will self bail with reasonable rain and if boat isn't laden with gear. It has a double hull, unlike the Beetle Gull.