I posted a link to this thread on Leif's facebook page and I received a message from his wife Stacy, part of which asked me to relay her appreciation for all the messages of condolence here. Rather than rephrase what she said, I hope she won't mind if I just quote the relevant part of her message:
It is very comforting to know how much Leif meant to you guys. I often referred to his flightsim as his "other wife" - and although it was often a bone of contention, I would never have denied him the great pleasure that he received from it. Leif and I were very, very close and I've heard about all of you over the years.
Just thought I'd mention, Rob has made an update on the home page at his Brit Sim website. If you care to stop by and view it you'll find a photo of Leif.