Forgot I already did a thread on this topic. That's what comes from having too many unfinished layout projects at once

The Shapeways one is definitely too modern -- I neglected to mention I'm looking for gates of 1953 or earlier. It shouldn't be too hard to fab up one from styrene strip. Make the entire gate out of styrene, but glue it to the NJI weignts and pivot.
Signals that guarded sidewalks also had small gates but on the same post just opposite the traffic gate. Haven't seen any of those in N either. Those might be hard to fab up and somehow attach to the NJI signal post w/o interfering with the main gate travel. Of course there were also separate mini-gates on their own posts for the sidewalk crossings.
With the double-wide gate version signal would be installed near the road and the sidewalk routed to the outside of it, with the mini-gate for that. Don't know how hard it'd be to build one of these things but it would be a nightmare to make operable!!