Having collected counterstamps for over forty years now, I'm seeing no immediate railroad connection with this READING, PA piece. I'll do some checking to see if there may be a listed merchant from Reading. At times, other c/s's can help with the attributions of mavericks like this one.
Given the smaller sized font of this c/s, I'm inclined to suspect the issuer, possibly a metalsmith, may have worked with small products, like jewelry, watches, cutlery, fine instruments and the like. Also, whoever stamped this coin took care in its placement, centering it on the obverse. This was a purposeful intent .... but why so, remains the mystery?