In the mean time, I have made a bridged solution in the KLH10 emulator
(using tap(4) + bridge(4). It can also be used with routing instead of
bridging, if you configure TOPS-20 right. (I haven't tried that yet but
it Should Work(tm).)

You can find the base distribution at http://panda.trailing-edge.com .
My patches are at http://www.falu.nl/~rhialto/klh-diffs2 .

(The default login is OPERATOR with password DEC-20, in case you can't
easily find that information in there)

-Olaf.
-- 
___ Olaf 'Rhialto' Seibert      -- You author it, and I'll reader it.
\X/ rhialto/at/xs4all.nl        -- Cetero censeo "authored" delendum esse.