I can't answer your question.
It is an odd name. The revolver is good for smokeless loads, although it will see few of those as long as I own it.
There are several other names that are applied to Uberti clones of the 1873 Colt.
"Running Iron" comes to mind.
I am wondering if these are actually translations of Italian names designated by Uberti. The phrases, "Smoke Wagon" and "Running Iron" don't seem to have the flair that we in the U.S. might identify with. But the words might mean more to an Italian. I am thinking this is much the same as some of the odd (to us) mannerisms in the spaghetti westerns. Just as those movies seemed over-the-top and a little off, so do the names Smoke Wagon and Running Iron.
I might add that the only place that the words Smoke Wagon appear is on an after manufacture "Taylor's sticker on the box.
I might also add that Taylor's price is a bit lower than the vendor on Gunbroker who appears to be buying them and then marking them up.
Taylor's wants 505.00 plus shipping plus FFL.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson