Yes, possibly you have a rifle chambered .25-20SS but mismarked as .25 WCF. The base dimension corresponds to .25-25 Stevens, however. Might be either. Only a chamber cast will tell.
I myself own a Low Wall marked .25 WCF but actually chambered .25-20 Single Shot, so this interests me. My barrel is definitely Winchester, and is definitely not linered. My action s/n is 47xxx; but what year that makes it I do not know. The barrel has no s/n that I can find. Did Winchester put matching s/n on the barrels, the way Stevens did? I'm not a Winchester expert.
I read some magazine expert in the last 2 years or so answering this same query by saying that these are genuine factory errors. Could be hoooey, could be not.
Due to the dating descrepancy of yours, I'm now wondering if they might have had a mess of .25 blanks made up and stamped .25 WCF, but not yet chambered, and when a rebarrel job came in they used one of those barrels but chambered it to the customer's request in one of the Stevens cartridges.
If the bore is shootable, get some correct brass and dies from Buffalo Arms and have some fun. The .25-20SS and .25-21 are actually pretty neat little cartridges.
If the rifle has a rough bore, use the 60 grain Hornady jacketed softnose bullet. You can safely run the velocity up to about 1800fps using XMP5744, which I use exclusively in my .25-20 SS, and also my .25-21. (Don't do this in a Stevens 44, it's not strong enough!)
One of my Stevens 44 1/2 rifles in .25-20SS has a bore that looks like somebody dragged a log chain thru it, but yet it shot that bullet into 1/2" 3-shot groups with that load. Be aware that that Hornady bullet is built too heavy to expand or break up at that velocity, and may ricochet.
If the bore is REAL nice you have a treasure, and should shoot cast bullets of about 85 grains, at 1200 fps or so. In any case, do not mess with that barrel - these are not at all common!