As pointed out in Paul Evans's posting, Mortl has been sending letters to JHR. The letters are not available on the site, but one of them was posted to alt.revisionism, and reprinted (without Mortl's name) in one of Zundelgrams. As you can see, he is an old-time, hardcore Holocaust denier.
Update: Lynda Mortl, his wife, wrote this letter to Irving. Her e-mail then: email@example.com
It appears in Irving's hacked list of contacts with Irving's comment: "Is OK Known to us".
Update 2: from Kulaszka's Did Six Million Really Die?:
And everyday as I watched defence attorney Douglas Christie, his legal assistant Keltie Zubko and the various defence witnesses make their way through crowds of hostile Jews, some of whom spat on them, as I watched them being savaged by a hysterical media, as I experienced the lynch-mob atmosphere of that trial day after day, I learned again and again what real courage was and what real dedication to the principles of a free society meant. It affected me profoundly. When the second Zündel trial began in 1988, it was no accident that I had also become part of the defence team.
Keltie Zubko is Lynda Mortl's Facebook friend.