Thanks for the input, all.

And an update: Alan Scholz from Bike Friday confirmed that they made the bike in the pre-Bike Friday years when they used the name "Advanced Training Products". It's a rare example of a TT bike from the Scholzes, but I realize that rare doesn't mean any more valuable, except maybe to a big Bike Friday fan.

His recollection is that it took a 700c front wheel, but I agree with the comments that the seat tube angle suggests 650 might be more appropriate.