Thanks GetOrf - when I tried that with "heartstrump" and "diamonds" or the other way around I got a snotty FB message saying "we require users to use their real names blah blah"
So I picked Heather Diamond as close enough, and put HeartsTrumpDiamonds as my "other name" on my new profile, and the email address is my MN name. I am already confused but hopefully it will make sense to Frank whom I have PM'd with all this malarkey.
P.S. My RL name ain't Heather!