I was tentative on the ID for the watch Jaroslav has linked above and am on this one too as we don't have an advert showing this case/lug style
1965 Accutron Railroad (tentative). Still a dandy watch!
I don't see this one in the new accutron ads forum post, or in the main ad database. At least not this case anyway. There are now two of these on site though.
I also didn't see a single ad which had the "Railroad Approved" as part of the model name /number. Lots with this on the dial,in the ad text description, and I think one ad said something along the lines of 60 accutrons were officially "railroad approved" in USA, but it's still looking like the "Railroad Approved" model category we have is functioning like a catch-all for these watches.
Having said that, I'm still good with two ticks for 1965 Accutron Railroad Approved, unknown model number.
Thanks for entering all these great Accutrons into our database!!! The watches and pictures are first rate!.