Hello all ..
Royboy ..I do not think Athearn ever offered an engine in O gauge ..in fact I think they phased out all O scale about the time they brought out the rubber band drive F unit in HO .
Bob thank you for mentioning the south of the border F units ....I've heard of them ...but never seen one ..perhaps till now ... I'll start flipping through OSR ...to see if the Mexican F units appear ....
Cheers Carey