Hi Mark,
I assume that was 280 kias when you started your decent? Mine always seems to speed up once I start my decent, probably because I don't bother to slow down before starting the decent. That's what led me to my conversation with Lou about using inflight spoilers. You read that. Adding to realism as it was "back in the days", can you turn your GPS off so you can't see the GS? But it sounds like the approach you described was almost spot on. That's great.
I would like to get approach charts as well. FSX doesn't give you much vertical information in the flight plans. As an example: I did a flight from Spokane, Washington, KGEG (USA) to KSEA. Following the 3:1 rule in starting the decent and maintaining 2200 fpm at 300k, I would have crashing into the Olympic Mountain Range just East of Seattle if I hadn't been looking at my radio altimeter. I did follow altitude assignments as per the flight plan. And I did find myself using spoilers to keep the 707 slowed. Next 707 flight I do I'll try slowing down before the decent as Lou suggested.
So yes, some more accurate approach charts would make this a lot more realistic and take the guess factor out if it.  There's just not enough information provided by Microsoft. What do you think?