chuckn,
I don’t think it is that bridge, although it could be.
I found one set of instructions #71-2968-250. Entitled ‘Railroad Bridge’
It shows only one pier support.
But, going through my parts bin I found the embankments pictured below
Also shown are the pier supports in the forground.
I was off by one digit. The supports in the forground and the grey walkway are from the kit you identified. It has a single center support. The brick abbutments and wing wall don’t look like anything I’ve encountered before. Most of the abbutments I’ve seen from Lionel/K-Line/MTH are grey.