Yeeeehaaa! Sorted!
No word from RTFM, but all the boxes can now see and talk to each other happily. Now posting from the SUSE box connecting to my ISP via Windows ICS and the modem on the 98SE box.
Bit of work with Google and a passel of configuration files and services but not excessively terrible. Quite interesting getting SUSE to join up smoothly into a mixed environment - 3.11 (WfWG), 98SE and NT/XP.
A D- for SUSE 8.0 on this aspect (a A for installation though) - a walk-you-through wizard would have been easy to construct. I certainly wouldn't have managed if I were a complete newbie to OSes and networking.
Now all I have to do is sort out the network printers and get all the Truetype fonts installed (the default screen fonts are awful).