hey Ralph
how about a look at the SG-1000 and SG-1000 II, I know you might just want to incorporate that into the Mark III/Master system, but they were different systems and some people have fond memories of them. It'd be like not having an atari 2600 but just having the later systems that also played 2600 games.
I also vote for a dedicated SG-1000 section
the fact that it was easy for you to code doesn't make it any less of a unique system.
if you could add that to the list in the first post of this thread that'd be awesome.