In 1999 Lionel produced a 305 Hellgate Bridge which was a little wider, 1-14", a little longer, 1-3/4" and a little taller, 1/4" than the 1928 original. It also had lighted towers. The idea was to take the 1928 standard Gauge design and modify it for 2 train O gauge operation on tubular track. It was also designed to pass through TMCC signals without interference. The 305 succeeded on both levels. The one thing that Paul Condeelis, the head of the project at Lionel, could not anticipate in 1998-1999 was the development of Fastrack.
We wrote about the development of the 305 in the Collector's Gallery in the December 2013 issue of O Gauge Railroading and the backstory is fascinating.
Rich Melvin even found a way to shoe-horn two FasTrack lines in the bridge while we were photographing it for Collector's Gallery. Read the article for more details, I think you will enjoy it. Yet another reason to subscribe!
pd, great to see how you were using the 305, and the LCCA tinplate set looks just right in that setting.
Ed Boyle