Hi Steve and Rick, and thanks for the input! You may have saved me from a bunch of wasted time. I was basing my decision to go with the taller seat on several photos I assumed showed an N.16, of which these two are among the clearest:

My reasons for believeing them to be a 16 were: a) the wedge-shaped top of the fuel tank like the N.11, I assumed all the 17s had the longer tank with the arched top, b) the fact that the motor was clearly a 110 hp Le Rhône 9J with rear-mounted pushrods and intake manifolds, c) the headrest on the upper photo, d) the center-mounted fuel and oil tank filler caps. But then I went back and looked closer...
The firewall on the 11/16, which had two lunette-shaped cutouts that let exhaust and burnt oil flow back and downwards through the aluminum "cheek pieces", appears to be solid—no cutouts—in the photos I was using. But the biggest clue was going back to the Windsock Datafile Nieuport Special, Vol. 1, where both those photos were clearly captioned as being N.17s.
Going back through my interior photo collection I can only find two that are unquestionably N.11/16s, and both show the shorter seat. And finally, I probably could've saved myself the trouble if I'd looked at the 1:48 Eduard N.11 I built back during the pandemic:

First rule of research: Check, check, and check again!
Thanks again guys.
Dave V.