I have a whole stable of MTH Premier PS-2 units with 16-ohm speakers that are slowly going bad. The picture of an old speaker shows how these things have disintegrated over ten years or so. MTH catalogs a substitute for the discontinued original for $18. I found another option from Parts Plus for 85 cents - 65 cents for purchases of ten or more, plus shipping. I bit off on an order of ten figuring I may need them at some point. They fit perfectly and sound great. With shipping, the repair works out to under two bucks per engine.
What an easy repair, too. Last weekend I set up a repair station in front of the big screen and went to work during afternoon football games. I work slow but can still knock out a speaker replacement and drivetrain lube per quarter of football. At this rate, I should have my GP38-2 fleet in great shape within a couple of weeks.