I actually found my number! I'm amazed I had a record of it hanging around in my old files.
7xxxx, 1xxx.
I thought so. If I'm not mistaken, 1979 or 1980? I think it was that early that I adopted. At least that's when I bought the TRS Model III. And if memory serves, I think it was only available during nightime hours during the very first year? I can't quite remember.