I have the
   source code and configed KDB into my new kernel source and attempted
   a build.  I got a psl unreferenced variable error in trap.c.

That's because you used the wrong option.  It's `DDB', not `KDB'.

   Then
   I tried to get the latest version of trap.c which eliminated the psl 
   variable problem but now has the sy_arglist (?) problem.

You can't just pull a file from -current into 1.0 and expect it to
work.  A *lot* has changed since 1.0.