Kansas City standard cassette recording

A number of years ago (heck, the prototype probably comes under the 10 year rule :-)) I designed a little interface to convert between audio cassette data (using the standard 1200Hz/2400Hz tones) and an RS232 port. I know I used it to read BBC micro cassettes and BASICODE recordings into a machine with an RS232 port. It works at up to 1200 baud. The Tx used a crystal clock and a set of counters, the Rx used the classic 2 monostable circuit. And I even used one of the handshake lines to turn a relay on and off to control the cassette motor. I can't find the physical unit, but I can find the schematics and parts list for it. I'd be happy to make one or 2 copies of this (but not many more) and to send them out. I'd also have no objections to further distribution, so if somebody wants to scan them and stick them on a suitable website, that would be fine. If anyone is interested, let me know.