If the "recreational" railroad folk have the necessary skills, but not all the qualifications/training/licenses needed in some cases (and of course appropriate union membership if it's a larger railroad) for direct hire by the railroad, I could see them being hired as casual labor for m/w crews by a dodgy maintenance contractor. I'd be very careful before signing on to that kind of deal, since willingness to take "somebody off the street" could lead to bad things. Like, among other things, lack of appropriate safety gear, adequate coverage for workplace injuries, and possibly lack of pay. Not sure how many guttersnipe contractors work for railroads, but they exist.