Funny you should say that, but after the last posting, I went to look, and found I still have the code documentation, and the listing I did of the assembler, mnemonics, and instructions, and calculation of the instruction times.
Documentation is written in troff, and is over 30 years old, and lasted a lot longer than the company I wrote it for.
I had actually remembered it wrongly - it was 128µs rather than 127 instructions, and therefore more than 127 instructions.