>Can anyone tell me how to set the "default gateway" on a 3494.

As I recall, this is done during 3494 installation, in OS/2 mode,
upon invoking the HOSTINST command, where a virtual "flip-book"
will appear so that you can click on tabs within it, including
a Network tab.
After installation, you could  cd \tcpip\bin  and enter the
OS/2 command 'tcpipcfg' and click in the Network tab, which I
think will have that setting.  I last did this years ago, and things
may have changed...
   Richard Sims, BU