So much, or so many.

The first example would be the 650b conversions prevalent on this forum. The second would be the fact that those conversions are patterned after the constructeurs of vintage French bikes. Then there are the touring bikes of the late 70's and 1980's (including the 650b Raleigh models). And the fourth might be the sub-genre of vintage mountain bikes with drop handlebars like the work from Charlie Cunningham or (some model years of) the Bridgestone MB-1 or the Specialized RockCombo.

Or even many of the drop-bar hybrids of the 90's, if you want to push it.

Even many of the British steel "road" bikes of the late 70's could fit wider tires that might grade into "all-road", depending how you define that.