I almost chose to not model the Adena area on the NKP's Wheeling district due to one thing, lack of inexpensive/easy to find Wheeling & Lake Erie-type Berkshire. In my mind the ex-W&LE K-1 Berkshires were a signature engine that would easily identify my layout as set in the NKP's Wheeling District. Renamed into the Nickel Plate's S-4 class and numbered 801-832, they looked similar to NKP Berks but with a few differences such as the disc-like Boxpox drivers. Without this engine I felt like it would be like trying to model the 1950's Union Pacific in Wyoming without it's signature Big Boys.
Eventually the urge to recreate the NKP's coal operations in Appalachia Ohio became too irresistible. Research proved I could fill the S-4 engine gap with S and S-1 Berkshires, H-5 and H-6's Mikados that were bumped to the Wheeling by new diesels arriving elsewhere. The remaining I-3 2-6-6-2's, ex-N&W 4-8-2's and M-1 Heavy Mikados would help mark this layout as Wheeling territory as those engines never left their home rails. With this new approach to building a steam roster I could bide my time and wait for an opportunity to acquire Key Imports NKP (exW&LE) S-4's or possibly figure out a way to kitbash the Proto 2000 or Bachmann Berkshires into a S-4.
Finally this past fall, thanks to a fellow NKP modeler switching to O scale, I finally managed to add a S-4 by Key Imports to the roster. Hopefully over the years to come I can add a couple more to my fleet, but for now she's my pride and joy!