@tim7, You are right - I was flipping the wrong bit of the nibble. 0xe0 it is.
@Constantin, Hadn't got that far yet. Still working on getting 2 uCs running of 1 crystal so I can some boards ordered. I think I have enough jumpers/headers on the board so any of those kinds of comm's can be set up.
See the schematic in Reply #9 of this thread. Have to tweak the crystal connections a little - xtal2 of chip1 will feed xtal1 of chip2. chip2 will have fuses set to allow external clock.
Think I'll do the connections with solder jumper pads so the two can be isolated if needed.