Williams and K-Line made Lackawanna passenger cars and freight cars suitable for that Camelback. I have seen them at the York Meet and Spring Thaw / First Frost Meets on the Allentown, PA, Fairgrounds.
Larger, more powerful locomotives bumped Camelbacks from fast, heavy trains. But they served well on branch lines and on locals. Adding to Hot Water's post, the Jersey Central used 4-6-0 Camelbacks on commuter trains at Jersey City well into the 1950's. No. 774 pulled three excursions as the steam era ended there. A dynamo atop their tenders at the rear supplied electricity for heat, lights and fans because commuter trains didn't run far or fast enough to keep the batteries on each car charged. There were also long layovers between morning and evening commuter trains.
Another option is custom painting. CJB Custom Painting & Designs painted 4 of Walter Matuch's RMT streamliners to match my 2348 M&StL GP9. They looked so good I got a K-Line Diner and a Pullman (blue and silver boxes) at York and she painted them. Their window silhouettes had seen better days. She made and installed new ones. Get some cars that look good behind that Camelback on a branch line or on locals and have her paint a Lackawanna consist. Her email address is cbraden77@comcast.net