If you're not looking to build another layout, how about writing and administering a tutorial section of the forums? I think it would allow you to continue providing the very valuable information that you do and serve as a great creative outlet for yourself.
Good looking bridge. I think the look is borderline on whether it appears strong enough visually. For a shoestring mining operation on narrow gauge I think it works as is. If you do decide to add structure maybe you could just do angular kicker braces (Rail?) on each side rather than full on vertical columns.
After those then the layout will come down.