[TUHS] Lions' Commentary Revisions?

I hope everyone's having a lovely tail end of whichever season is gracing your hemisphere. Had some surprise snow this morning up in the NW corner of the US, hoping it bodes well for a mild summer. I'm curious, is anyone aware of any attempts to revise John Lions's UNIX Commentary for versions beyond the Sixth Edition? Having finished my disassembly of the classic video game Dragon Quest this past year, I'm now doing some planning for a similar work and have considered practicing the art a little by doing some diffing of V6 and V7 and feeling out the process by putting down some revisions, that way I've got some of the flow and kinks worked out before I start on my own "Commentary on Dragon Quest" manuscript. I'd hate to double up on something someone else has already done though, so if V7 for instance has gotten this treatment, then perhaps focusing on PWB or the CB-UNIX kernel would minimize the potential rehashing. Also if anyone has any thoughts, suggestions, etc. from their own experiences working up very detailed source-level documentation of a large software product, I'd certainly be interested, as I know this is going to turn into quite the sprawling undertaking once I really get going, especially if I try and work in the differences between the Japanese and U.S. releases (of which there are many.) - Matt G.