Well if you look at the first picture the top of the Girder bridge side shoud be above the gards van roof rather than harf way up the side and would probably go from river bank to river bank.
I suspect the the Girder bridge side you have there are some 2mm/foot "N" rather than 4mm/foot "OO" peco probably I'm sure that some one here can find another picture example of a "OO" girder bridge.
Thats all but thats my opinion if you happy with it who cares what anyone else thinks.
Pete