Yeah, Mark Adams was a wonderful player, but I'm not sure it was him playing Bass on 'Inside Out'.
I do seem to remember someone saying it might be Sandy Anderson on Bass (around the time of the single release).
Maybe this 'TalkBass' thread might shed some light and answer the question?
https://www.talkbass.com/threads/sandy-anderson.788720/
For those that don't know, Mark Adams had a pretty traumatic life with booze, drugs and depression. And of course his terrible murder in 2011 (three years after this thread was started).
A bit of a depressing read, but nonetheless, interesting.
https://www.iloveoldschoolmusic.com/sad-see-slave-band-member-died-family-wants-answers/