Glenn and Pete make a very important point about the NFA status of the 15" Lightweight Carbines. Restoration to original status may be WORSE than impractical.
As for the rifle you have, I believe the only thing that shows it once was a Lightweight Carbine is the saddle ring stud hole. The "grooved" reciever ring is common on early lowalls. My quick perusal of John Campbell's books didn't reveal when the lowall recievers stopped having the groove; he simply says it was dropped in later production.
Likewise, Campbell doesn't give any production number for the Lightweight Carbines (that I could find). They are not common in the US, that's for sure. However, that may just mean that many were worn out or lost in Australia, where they seem to have been most popular, or elsewhere. They were the cheapest Winchester centerfires for quite a while, and probably many were worn out in sheep camps, by trappers, and by farmers. When they were reduced by use and neglect to rusty wrecks, many were probably converted to .22 Hornet and other varmint calibers or to .22 RF like yours. Once the NFA declared these "weapons of mass destruction" or whatever they are presently classified, some of the survivors probably promptly lost their short barrels for "legal" length ones, too.
I doubt if most of us (me certainly) would be able to ACCURATELY determine a Lightweight Carbine reciever if shown just the reciever. The unique sling stud hole would just be an "extra hole by Bubba" to most, and would just make the reciever that much more likely to be used for a parts gun. Sad, but I think true.
If ever a rifle "got no respect," it was the Win 1885 in the 1940s and 1950s.....I FOUND one of mine (a Highwall) and was GIVEN another for free (also a Highwall).
