There was no specific date, you could order them either way for many years, damascus was usually the more expensive of the two. I'm quite sure though that any Lefevers made by Ithaca had "steel" barrels (although there probably were some Lefever made guns left over and sold by Ithaca). Ithaca acquired Lefever something around 1916.
1875.
With the serial number that you provided,your Ithaca double barrel shotgun with the damascus barrels was produced in the year 1900.
The phone number of the Damascus Library is: 501-335-8142.
The phone number of the Damascus Community Branch is: 301-253-5100.
The phone number of the Damascus Branch Library is: 276-475-3820.
In 1916, Lefever Arms Company was sold to Ithaca, who continued to make guns under the Lefever brand. Your serial number would date to around 1935-1937.
That is impossible to determine without more information. It should be a double gun with sidelocks. We need to know exactly how it is marked, including markings between the bottom of the barrels and the frame, what gauge it is, how long the barrels are and how they are choked, and most importantly WHAT CONDITION is it in (case colors, blue, wood, checkering, bores, etc. Send digital pictures.) Lefever shotguns can range from $300 to over $10,000. sales@countrygunsmith.net
Try: It may be stamped in the wood inside the forarm. You have to pull it free from the barrels to see it. I have J Stevens Dbl Barrel and this is where I finally found it.
Acier Cockerill is not the gun manufacturer, but the maker of the steel in the barrels. It means the gun has fluid steel barrels and not damascus steel. It probably dates from no earlier than late 1890's through 1940
The Ithaca Gun Company acquired Lefever Arms in 1916, and manufactured the Lefever Nitro Special between 1921 and 1947. The serial number on your gun indicates it is an "A Grade" made in 1937.
In order to determine the age of Lefever shotgun, the serial number must be known. However, Lefever shotguns were only made and distributed between 1885-1916.
Gun was made in 1915. Does it have damascus or fluid steel barrels? Gauge? Condition is everything... You can get a good idea from the auction sites such as, gunbroker.com or auctionarms.com.