I found this auction also and was going to bid until I looked up the serial number on the LC Smith site. The serial number is 214493. Which I think would make it a 16 gauge.
I called the auction site to talk to someone about it but they didn't have anyone that could talk to me. So I let it go. I would have paid that amount for it had I been able to talk to a person.
Other double gun auctions included"
LC Smith marked "L.C. SMITH 20 GA. SER.#36688 DOUBLE BARREL STOCK BEEN REPAIRED" that sold for $175.
Ithaca marked "ITHACA HAMMERLESS 20 GA. DOUBLE BARREL SER.#97317" that sold for $175.
One marked "BELGIAN MADE JENSSEN SONS DOUBLE BARREL 20 GA. SER.#9029" that sold for $130.
One marked "BELGIAN MADE MANHATTAN ARMS DOUBLE BARREL 12 GA.? PAT. 1892 SER.#9650" that sold for $350.
Lefever Nitro marked "LEFEVER NITRO SPECIAL 20 GA. DOUBLE BARREL SER.#224149 DOUBLE TRIGGER" that sold for $200.
Savage Fox marked as "SAVAGE ARMS FOX B-SE SERIES H 12 GA. DOUBLE BARREL SER.#C329191" that sold for $320.
Oh yeah, the auction was in Wisconsin.
JR