If you prefer to hack an adapter rather than go looking for one, the following
diagram and notes may help:
http://www3.telus.net/~bhilpert/tmp/MacVideoAdapt.gif
This was derived from the two-stages of off-the-shelf adapters
(Mac->VGA->13W3) I use on a similar beige G3 (with internal Zip drive BTW) to
drive a Sun (OEM Sony) 17" monitor.
www.everymac.com is pretty good for basic mac config & specs, i.e.:
http://www.everymac.com/systems/apple/powermac_g3/stats/powermac_g3_266_mt.…