max sciandri rode one when riding for motorola...i've seen a couple for sale over the decade...it's similar to what colnago did on some of the larger frames, known as freulers after pro rider urs freuler
i've got limited minutes left in life, don't waste my time
Looking at the relative head tube length and the very relaxed seat tube angle, I concure with zoikz that it is a frame configuration for larger riders, and Roubaix would could have been a likely engineering target for such a frame. Steve Bauer had Merckx build him a super laid back geometry bike, specifically for Roubaix. As far as the seat clamp, again, it is a very robust looking setup that would help endure the rigors of Roubaix.