Nostalgia PC using period specific model & engine (Fox PC .36, Testor/McCoy .35, ST C.35, ect...) a very good High Speed is 20 seconds/90 mph. The same period specific airplane model using a modern-day engine (Aloise X-.36, Nelson, Wiley, K&B, ect...) is 17 seconds/106 mph. The difference using the same period specific airplane model is 16 mph or (16 x 4) 64 points.
When the advantage gained becomes 44 points (64-20 bonus points), the reason why some are using modern day engines makes a lot of sense, however; doesn't solve the issue Nostalgia Carrier is not truly Nostalgia and needs a rules change leveling the playing field.
A bonus point structure of +70 points instead of the current 20, would favor period specific engines, limit the use of modern engines, lower engine cost, and truly make it Nostalgia carrier.