Who Made This Oiler?

[Singer B]

I recently acquired an M1 carbine via an auction. It is an Inland with a 340,XXX serial number. It is in a complete Type 3 configuration. It has the round bolt and a FATS stamp on the left side of the stock just forward of the sling well. It had a reproduction sling on it and the sling was secured with the usual oiler. I would like to identify the manufacturer of the oiler. It doesn't have the usual Roman numeral number markings and has a set of concentric circles stamped in the bottom and nothing on the cap. Can someone please identify this oiler? Thank you!

[Flying10uk]

has a set of concentric circles stamped in the bottom

It looks more like deep "turning marks" when it was "parted-off" or "faced-off" in the lathe during manufacture. Caused by an incorrectly set lathe tool or blunt lathe tool or incorrect spindle speed or the operator attempting to force the lathe tool through the work too quickly or a combination of some or all of these. My lathe work doesn't look like this because I take the time to do a quality job which some regard as wasting time and think that producing rubbish is good enough which the customer will be happy and grateful to receive.

I think that if you look more closely you will see that the marks are a "spiral" rather than "concentric circles".

I have used the term "spiral" correctly above as it is so commonly used incorrectly. A "spiral" is flat and does NOT increase in length. Where the length increases, such as a screw thread, the correct term is "helix".

[W5USMC]

Your pictured oiler looks to be a reproduction made for the commercial market. I have a few in one of my parts boxes just like it.

It doesn't have the usual Roman numeral number markings

Not sure I have ever seen an oiler marked in Roman Numerals?
Oilers made by International Silver were marked, II, IU, IW, IR, IN, ISP, IQ and IS.
SW oilers marked on cap, unknown maker, possibly Stanley Works?
BK marked oilers were made by Blake Mfg.
Poley Bros. & Verson oilers had a unique bullseye and arrow marking surrounded by their name as well as the words Precision Built.
South Korean oilers were marked SN over 76, KJ over 76. Korean writing over 77
Unmarked USGI oilers were made by Yankee Hill Machine (Vietnam era)