"The Shuttleworth Collection has a Triplane. Have you asked them?"
Thanks for the suggestion. I'll try querying them.
"There is also this board, http://www.theaerodrome.com/forum/ if you haven't tried yet."
Yes, I tried registering a few days ago but got the message that a scammer-detection database they use was down, so I'd have to try again later. Interesting how security tries to keep up with the bad guys. Thanks for the reminder. I'll try them again.
"Did you know that the Triplane had variable stab trim (like on the Bf109)?"
I noticed that feature during my research. Plus and minus two degrees, if I remember correctly. Will have to build that into my model. Probably will have to use the trim-tab feature. I don't think X-Plane has the "flying tail" component; will have to check.
Great discussion, guys. Thanks to all.