Here are some photos of the two bridges side by side, both are now essentially done.
Bear in mind, these are going on an American Flyer toy train layout.
The layout owner needed a curved span to cross a curved track beneath, and I offered to make him a basic span that would work for that as well. The curved portion of this bridge is not my specialty, but it works.
I made the curved portion to physically separate from the stone arch portion, and be held in place by 4 super magnets, which worked out well. It is very strong. One thing about super magnets, they work especially well in pairs, obviously of opposite polarities. They form a much stronger joint when they mate with each other, as opposed to mating each one with a piece of metal. They can even be used in multiples, and their bond strength increases dramatically. They form the bridge shoes, if you will, on this bridge.
Wood underlay forms the base of the curved section, and the sides are fiberglass, which curved nicely, and I had hoped would cooperate and resist the need for screws, but both super glue, and hot glue failed on the inner (tightest radii), and to my dismay, I had no choice but to mechanically join them, hence the screw heads. Bummer!
He is satisfied with it, so I am happy, but I have to give that more thought before the next one. It was pretty much the first attempt for me at making something quite like this, and like I said above, not my specialty, but it gave me experience, and food for thought. I offered to add a railing to each bridge. Again, these only needed to be finished on one side, with a downward viewing angle.