Contacting Mark Wong

I'm sure at least some people on here are familiar with Mark's work... he's done some fairly awesome pics of existing and custom G1 transformers. A few years ago I was developing a Transformers boardgame (even had Steve Jackson interested for a bit) that's basically a cross between Battletech and Car Wars. I toyed with attempting to get a Transformers license but the costs proved prohibitive (especially once the first live action movie was announced and the franchise got big again).
Anyway, I decided a couple of months that, since I have this complete (and fairly fun, at least we thought so :p) boardgame hanging out on my desktop, I might as well just release it for free and let people enjoy it as they will. Problem being - it uses a lot of Mark's artwork. And though we discussed compensating him if I did manage to get the game published, now that I'm releasing it for free I'm not comfortable publishing it with his work still in it without his permission. Problem? I can't seem to find a single reliable contact e-mail for the guy. :0
So, if anyone knows how to get in touch with Mark or could point me toward a website I may have missed, I'd appreciate it. I'd hate to release the game manual without his artwork, as it just seems.... well, flat, otherwise. Thanks to anyone who can help.
Anyway, I decided a couple of months that, since I have this complete (and fairly fun, at least we thought so :p) boardgame hanging out on my desktop, I might as well just release it for free and let people enjoy it as they will. Problem being - it uses a lot of Mark's artwork. And though we discussed compensating him if I did manage to get the game published, now that I'm releasing it for free I'm not comfortable publishing it with his work still in it without his permission. Problem? I can't seem to find a single reliable contact e-mail for the guy. :0
So, if anyone knows how to get in touch with Mark or could point me toward a website I may have missed, I'd appreciate it. I'd hate to release the game manual without his artwork, as it just seems.... well, flat, otherwise. Thanks to anyone who can help.