Dear Cal,
No, not very clearly at all. Consider a reductio ad absurdum: wide-angle lenses have a much bigger image circle than standard lenses, but rarely if ever offer the very highest quality in the middle of that image area, as compared with a lens with a narrower angle of view.
There is an enormous difference between circle of illumination and circle of sharp resolution. Some lenses fall off very fast; some remain acceptable a long way out, though of course "acceptable" is a bit of a weasel word. A bigger image circle is easier with a slow lens, and a 65mm lens is very close to the 70mm diagonal of 645, so I'm not surprised that it can be used successfully on the Pentax.
Having met a fair number of lens designers, and understanding a modest amount about lens design (including the existence of telecentric lenses) , I'd be very surprised indeed if it were in fact derived from a lens for a larger format, except perhaps in the sense that Tessars existed long before 35mm. But the reason it's 65mm is that 65mm is the shortest lens that will allow infinity focus on a Visoflex.
Cheers,
R.
