Bob,
I was not the one looking for the decals (that was Gerry)- I bought several sets some years ago, and still have enough for my Blue Bird kitbash and plenty left over for the cafe-lounge. I bought my decals from Gary Roe, who had them done by Rail Graphics, who made the ones that Mark Vaughn sells in HO.
Great value, actually, as each sheet has enough decals for 6 or 8 cars (if you are careful cutting) and virtually every car name owned by Wabash. Yellow, in the UP style font that started being applied in 1954. No idea if he still has them available, but I would think if there were enough interest, someone might do another run.