Having found a suitable emulator, I thought I'd share it,
and some ideas, with the group.

Without further ado:
http://www-scm.tees.ac.uk/users/a.clements/software.htm

The University of Teesside  Simulator & Cross-Assembler package
works just fine under dosbox on Linux (which is to say, I *assume*
it runs just fine on a real DOS/Win box.)

As with most other sims/emus, it uses TRAP #15 to implement
'system calls' - terminal I/O, serial I/O, and file I/O.

My rough ideas for CP/M68k are to use a virtual COM port
which emulates a disk drive via a protocol similar to older
Commodore or Atari drives.

Bootstrapping such a system is left as an exercise, I will work
on it as time permits.

TTFN,
  Tarkin