Such a huge undetaking...bound to be glitches along the way, but a massive stepping stone/useful tool for sure. Whether to include the non-Soul output on Soul labels is an easy one for me...include them but state that they are not Soul.
I have complete empathy for any project like this, as I am (still!) deeeeeep into my own book concentrating on 60s US Soul released in Japan at the time. Fortunately (or not as the case may be!?), the number of releases is smaller than the US and a lot more compact to research - i.e. there weren't any small labels doing limited runs and all releases came through the same half a dozen or so major labels. Still, it takes a LOT of time going through the company files/catalogues in search of the Soul titles amongst the many, many Pop releases...not to mention it is not in my native language!
Then the questions concerning what to include, how much background to write about the manufacturers, the routes to market, the advertising budgets, the sales/pressing splits between formats, the number of people living in Japan at the time who had a radio etc etc etc and etc come into question!
The editing and never ending label/sleeve scanning continues!