Hello, I have this frame and judging by the lugs, it's a Claud Butler but I can't find the model since the fork has a huge rake and the seatstay end has an odd shape. The frame was modified by a previous owner to be a fixie so the cable guides are missing. I think there was a cable pass over the bottom bracket (swiss threaded) and it could've had a derailleur hanger. I used this frame as a fixie for half a year.
The fork threads are english and the rear wheel spacing is for 5 cogs cassette. I think it was for 650 wheels since it requires long reach calipers for 622 wheels.