I couldn't get it working..Seems like vanilla wallets can run on any port, but not masternodes.
I also couldn't reliably get 1 wallet to run more then 1 MN.  I'd always end up 'unable to allocate VIN'
or some such.  

After jerking around with it, I finally said screw it, and create 1 wallet per mn
wallets can run on alt. ports - doesn't appear MNs can.  This setup has run
stable for a few days now.

edit: number of masternodes is going up fast too.  already 93 running.