Autumnsky, I worry about the carpets and floors every day. I lucked into having a landlord who is an aquarium enthusiast, too, so he has never looked suspiciously at the multiple tanks in the house. But I do worry about keeping everything water-tight.
I got inspired by the responses here and started on some rockwork for the scape on the left, and also pulled out the railroad pieces again. Maybe a bit at a time. Current problem, besides the leaking bridge, is meager plant growth following an outbreak of Cladophora. The algae is under control now, but I need to make sure I am balancing everything so that it doesn't return and the plants can grow back. I recently added some pothos in the filter baskets in the back of the tanks, which I hope will help.
Cria, thanks so much for your thoughts. Actually, the bridge is made of 1/8" glass. It was cut at a hardware store, and the cuts are a bit rough. I think a big part of the problem was my inexperience in sealing and the order in which I siliconed the pieces together. Some of the most important, water-bearing seams were the last ones sealed, by which time it was difficult to reach inside the bridge to do them smoothly and evenly. I am rethinking the process of sealing everything so that the most important areas will get sealed first.
I'm looking forward to working on this project again. I was surprised and touched by how much the gourami really, really misses his bridge, so I'd like to get it up and working for him again soon.