Sept. 1975 - P&W in E. Hartford was holding an open house in recognition of its 50th anniversary. For the public display they invited one each of most surviving P&W-powered aircraft, complete from the late 20s. I was mostly interested in the radial-powered equipment, and pleased to see a hangar full of one each of most every engine Pratt ever built.
The elephant on the field - Rentschler Field, 5000' runway - was the UAL 747-100, flown by a Boeing crew with recent short-field experience.
(My funnybone was tickled by a couple of Sikorsky SH-3 and CH-53 interlopers, bearing no recognition of their Brand X engines)