I've followed this thread with interest and decided to offer my .02. IMHO the forend is aftermarket--most importantly because sxs beavertails weren't available until 1920. Also, the checkering patttern is nothing like a 3E pattern, despite the number stamped in the inside. This was commonly done by the stocker to keep the gun "authentic".
Secondly-- the trigger.
The entire gun has been refinished (I hope that's not hot blue!), and shows little use after the refinish. Likewise the trigger shows no wear, which leads me to believe that it was plated when the gun was refinished. As an aside I own an original 1912 catalog that makes no mention of gold-plated triggers as an option.
I could be wrong but we often say "never say never" when speaking of Smiths!