Picked up another XVI today, this one with a couple of interesting things to report.
First off the owner had replaced the original green/red 2-colour LEDs with red/blue ones. I'd never seen a single two-colour LED that included blue, so I opened it up and found this crazy mod (http://nfg.2y.net/grafx/XVI_LEDs.jpg). He'd replaced the original single LED with a dual LED setup. Quite ingenious I think, though they're quite dim... Have to do this with mine. Only not so dim.
Secondly there was a SIMM memory adaptor inside:
(http://nfggames.com/grafx/xsimmvi.jpg)
First time I've ever seen an XSIMMVI up close. They crop up for sale now and then but they're not cheap. Finding one inside was a bit of a score, I think.
The system included a 275MB HD loaded wtih utils, a 120MB superdisk drive, and a CD ROM. No media for either of the latter two. Crazy seller included ~200 floppies, none labelled except with the occasional post-it strip attached to the sleeve. About 25% of these discs were new/blank. Weirdo.