There is a bit of a connection between PRR #4483 and NKP Berkshires. In a different timeline, I would have been visiting NKP #757 at Hamburg, and not a PRR Decapod.
PRR #4483 was retired in '57 and placed in storage at Northumberland roundhouse with PRR's so-called Northumberland Collection in 1959, destined for preservation. At the time, there was no real plan for where they would be preserved, just that the PRR wanted them set aside. In 1962, Westinghouse Air Brake Company came to the PRR and desired to purchase a steam locomotive to park in front of their headquarters in Wilmerding, PA. The PRR sold them #4483 and the business car Ohio, and they were moved to Wilmerding and placed on a display track.
Around the same time, in 1958, Nickel Plate took a bunch of their retired Berskhires and ran them through their shops for complete overhauls, and then placed them in storage. The NKP was concerned about a future traffic surge that would overwhelm them, and so wanted some steam engines placed in reserve. The traffic surge never materialized, and so by 1962, NKP started selling off the zero-mileage engines, either to cities and museums, or to scrapyards. Bellevue, Ohio was NKP's big home terminal and was offered NKP #757, but Bellevue did not have a place to display it. After several failed attempts at putting together a display location and the buyout of the NKP in 1964, the Norfolk & Western finally said enough was enough in 1966, and instead donated the #757 t the Railroad Museum of Pennsylvania in 1966, making it the first locomotive donated to the museum. (The Northumberland Collection, sans #4483, would be donated by Penn Central in '69 and even then, the RRMoPA was a secondary choice, they wanted them to go to St. Louis first to join the PRR P5a electric there, but the deal fell through when the PRR rep accidentally ran over the museum curator's cat!)
In 1983, after 20 years of deteriorating outdoors, Westinghouse Air Brake Co. decided to sell off PRR #4483. Somehow the Western New York Railroad Historical Society was the lucky buyer. It's surprising that the RRMoPA weren't the ones who bought it, since #4483 has always been viewed as the "one that got away", the only surviving class of PRR steam that they don't have represented. I have to assume it came down to a matter of finances. The WNYRHS wanted the #4483 because it did historically operate in western NY, on PRR's Elmira branch, hauling coal from Elmira, NY up to Sodus Bay. It was then moved to Hamburg, NY, where it is today and is undergoing a slow cosmetic restoration.
Meanwhile, #757 was largely ignored at the RRMoPA, often being dubbed "The Forgotten Berkshire". Off the record some museum staff stated that #757 was a "outsider locomotive", since the NKP had only operated 90 miles of track in PA, mostly in the northwestern corner in the stretch between Conneaut, OH and Buffalo, NY. The other issue is that the museum, for all its good, sometimes seems to forget they are the Railroad Museum Of Pennsylvania and not the Museum of the Pennsylvania Railroad. Equipment not from the PRR often seems to be considered a low priority for restoration and preservation. So #757 sat outside without much in the way of love, and even had parts borrowed off it for both NKP #759 and NKP #765.
So where do these stories intersect? Well, according to some museum board members, at some point in time the idea was floated to trade NKP #757 for PRR #4483. On paper it was advantageous for both. For the WNYRHS, they would get an engine that had more of a historical connection to the area, as the NKP had a larger presence in the Buffalo area than the PRR. For the RRMoPA they would get the final piece of the Northumberland Collection and it would be back on PRR home turf. The downside to this trade was that the RRMoPA would be getting rid of their only road locomotive that wasn't owned by the PRR, as well as the newest and largest steam locomotive they owned and the only example of Superpower in their collection. In the end, sentimentality won out, as a number of the board felt that they shouldn't get rid of the very first locomotive donated to the museum.
Curiously that sentimentality did not hold out forever. After a number more years deteriorating, the decision was made to donate NKP #757 to the Mad River & Nickel Plate Railroad Museum in Bellevue, Ohio. The logic was that it was one less piece of equipment to have to maintain or restore one day, especially as it was one they didn't feel was relevant to their collection. Plus, #757 would end up in Bellevue, where it was originally supposed to go, and with a group who was planning to restore it cosmetically ASAP. It had the rods removed, all of its journals liberally greased and was moved back and forth on the Strasburg line to make sure everything was freed up, and then was towed to Bellevue by Norfolk Southern, including a trip over Horseshoe Curve. In the 4 years since, the MR&NKP Museum has made great strides in getting #757 all painted and cleaned up.