Just a quick update...

Using sadmanonatrain's wonderful guide on cleaning and lubricating the 400k drive, I was able to remove the "amber" that had seized the mechanism! I was astonished how hard the grease had become. I few hours with the wd40 and a stiff brush finally did the trick.

A healthy application of white lithium on the moving bits, and I have a smartly ejecting drive. A quick clean of the head with 99% isopropyl, and this thing is just like new!

Now to figure out how to get some software... MacPaint is great, but a bit limiting!