Mark said: Isn't the Bb° notation usually employed to designate the diminished 7th? If this doesn't come through, I used the degree symbol, a little circle above and to the right of the flat sign. A plus sign means augmented, a minus sign means minor and the degree symbol is the diminished 7th.

Exactly, and that's how most jazz transcriptions are written. You are correct. Also, a 7 with a dash through it, indicates a major 7th.