For future reference, the distance between the pin holes is right at 7/8". It's probably the metric equivalent, but my machinist's ruler is marked in inches.
eBay to the rescue this evening. A salvage operation in Ohio called Pinwall Cycle Parts had a set of front pegs off a '97 VN750, including the mounting hardware, shifter lever, brake pedal, etc. for $29.95 with free shipping. The cheapest new parts I could find were going to run me right at $80 + shipping for both sides, so I decided to gamble on the condition of the used parts.
Took a close look at the Kuryakyn 4351 premium floorboards with 8813 splined adapters. As best I could tell, I don't think it's possible to position the right side floorboard far enough toward the rear of the bike to avoid interference with the brake pedal. For anyone "on the fence" as far as trying Knifemaker's floorboards, they're a bolt-on guaranteed fit: had occasion this evening to note the more subtle aspects of the design that make it a bolt-on fit, and was impressed all over again :-).
The Kawasaki Fire & Steel floorboards (part number K46000-405) are scarce as hen's teeth and prohibitively expensive when they can be found. I actually found a few sets today, but none of them were under $340.