As a 6'-8" CR member I can't help but stand up and speak to this thread. (Ooooo, sorry...stood up too fast, got dizzy. Just a second....there, I'm better now)
The bike on auction is remarkably similar to one I have hanging in the garage which was built by Jeff Linsday in Chico California ( later he was seminal mountain bike maker Mountain Goat...) in the early eighties. Biggest difference ( as was pointed out) is that my mixte stays are halfway up the head tube. Don't know about the engineering myself either, but the esthetics are certainly better. I have long suspected that the mixte tubes cost a lot more in weight penalty than they add in stiffness. Especially with modern big diameter or conical section tubes. My steel 68.5 cm Della Santa is almost that big at half the weight and much better riding as you might expect.
The thing about the shift levers tho.... One thing folks always seem to forget it that when you have legs that long, one's arms are quite long too. So reaching down? not a problem. I set my version up with bar-cons and rode it during the pack-mule bikecentennial craze. I fondly recall crossing Ebbetts & Pacific Grade in the Sierra with a fully loaded pannier laden 80 pound load in the middle of Winter, just before they closed the pass for the winter... oooo I digress.
The long arms.... I've run into the same issue the few times I have attempted golf. No, I don't need longer club shafts. I can touch my toes, just like you should be able to!
Wheelbase does become an issue with the long legs. Top tubes don't need to be as long as sometimes supposed though, again, the arms are real long and the base of the triangle of upper body/arms/top tube just doesn't need to grow that much. My biggest issue is that frame designers seem to think that the head tube must be alot steeper. My 70 cm Cinellis have a 75+ degree head angle, while my much better tracking and handling Frayer (KOF wannabee-the bike I've raced on about 100 times in the last two years) has a 72.5 and I find it corners fast and tracks straight all because the trail is correct. Steep head angles and wrong trail: thats the shimmy deal you experience with big and bigger bikes. It is a trick to get all to work tho.
Yours in gigantism
Riccardo Bulissimo
Verdi, home to some of the world's biggest bikes, Nevada