Just adding to this. I came across him in the 70s through articles in Military Modelling, (IIRC).
I think in this time when we all have internet access, email etc. and clubs and vendors are a few clicks away, it's easy to underestimate just how crucial things like Battle, and Practical Wargamer were to building the hobby. Especially if you lived outside of London or a major city, there were no conventions, shops were for railway or military modellers first and foremost, and magazines were the lifeline for many of us.
I occasionally have the privilege of playing with Charles S. Grant, and he has written a very fine eulogy for Stuart, published by Henry Hyde on his Battlegames site. It's worth a read, and it's also a sobering thought that we are now losing that second generation of notables from the hobby.
Future notables have big shoes to fill.