Re: Winchester Model 141 .22 SL or LR
The 141's true value is as a shooter - as there is very sparse collector's demand for them.
If your rifle has no serial number, then it was made prior to the GCA-68 mandatory serial-numbering requirement of 1968.
Prior to 1968, many manufacturers didn't bother to serial number their economy, and/or less expensive firearms - although some did.
In the mid-60's, Winchester went on an "economy" kick, introducing several "affordable" products from 1963 onward - the cusp of "pre & post" '64 references, when speaking of Winchesters.
Besides using less expensive internals and manufacturing methods on most of their firearms, Winchester also introduced a series of inexpensive rimfire boltguns to replace the discontinued Model 69, etc line - which was their previous economy model.
Your M141 butt-loader was introduced along with the M131 - but were discontinued in 1972 in favor of the Greg Warne designed Model 320 series - which eventually went on to become the Kimber.
If you ever decide to refinish it at some point, due to damage in the future, just be aware that it's stock is a very blonde/yellow "hardwood" under the issue stain.
I once made a nice-looking (subjective) sporter from a M131 by adding a rosewood forend tip & gripcap to contrast with the yellow wood, ditched the sights, and restyled parts of the stock for a more graceful line.
With those smaller, properly-proportioned scopes, they're pretty good handling little rifles.