Hi,

first, many thanks to all who answered my cry for help!

>   Maybe build a personalized kernel?  Docs on how:

that was just the thing I wanted to avoid, since the power of that old laptop 
is very limited. Sigh ... did it anyway ;-)
So it took about 6hours to compile the kernel and deps, with the specific 
PCMCIA-options set - and voila: it really worked. I had to set the media type 
of the D-Link-Card (ne0) by hand, but if I remember correctly, I had to do 
this with my first installation, too.

So, knowing I CAN get it working with 1.6.2, I tried another clean install 
from floppy (no CD-Rom usable in this ancient rocket-like machine), 
installing also the comp.tgz-set. When rebooting the first time, I did NOT 
alter the kernel-options using (boot -d), well knowing that my network will 
be screwed up. After the boot, I just used gdb --write /netbsd - and this 
also worked! Halleluja - seems to be some kind of wonder/magic.

This allows two conclusions (at least to me, having VERY limited 
NetBSD-knowledge): either installing gdb with the initial comp.tgz-set has 
some significant differences to the mere package-install of gdb - or it is 
simply not possible changing the kernel-values during the boot (via boot -d) 
AND THEN trying to change them permanently with gdb --write /netbsd also.

This question may remain unanswered - I for my part am happy to have my 
gateway up and running again.

Thanks again,
Kai