Wolv, the eraser (pencil eraser seems to work better, but the gum eraser also works) has worked on all the Athearn units I've tried it on so far, locos and rolling stock. With as many railroads as you're running, Wolv, five MOPAC locos might be enough for now. If you're looking for more info on the locos they run, the best website is as follows: http://www.trainweb.org/screamingeagle/ I've also got the book "Missouri Pacific Diesel Power" in my hands now, so any info you want on their locos feel free to ask. I'm still assembling their actual roster as of JUNE 1980 based on the info in the book, it's taking some time obviously. So far I've got the two GP15-1's, an SD40-2, and a GP35. At the top of my wishlist is an Atlas U23B.