Locomotive stuck in reverse

I have a 50+ yo Marx model #52875 locomotive (2-4-2 no. 666) that has always had a problem getting stuck in reverse. I have always been able to get it out of reverse the standard way of switching it off and back on. I have recently pulled it out of “mothballs” and it is stuck in reverse and doesn’t want to change polarity in no way, shape or form. Is there a secret method that I am not aware of that will reverse the locomotive so it will go forward?

Try the following articles http://cs.trains.com/ctt/f/95/t/92430.aspx http://cs.trains.com/trc/f/1/t/281077/reply.aspx https://dfarq.homeip.net/repair-marx-reverse-unit/ Apparently this is a common problem. If yer lucky, a shot of tuner cleaner will fix the problem. Otherwise, the articles point the way forward. Good luck!