polish Radom refurb (11 factory stamp).
A Radom refurbished SVT-40? I think that this is likely a fake / fraudulent marking unfortunately.
No, the Poles kept the SVT-40 in service well into the 60's, (mostly at officer training academies and as ceremonial rifles, but they remained in active inventory) - they refurbed a great many SVT's.
Wilkas/Wilkolek reworked bayonets, and even made fresh bayonets.
"Radom" wasn't a factory, that's a misnomer. It was/is a city in Poland with a wide variety of arms industries. They did a lot of refurb work over the years, from Mosins, to SVT's, SKS's, among other things.
Referring to the city is common practice. Izhevsk isn't a factory either but you don't see a lot of people selling "Factory no. 74 91/30s".
I don't doubt that Poland was given SVT-40s in the 1950s but I've never read nor heard anything at all about them marking SVTs with an 11 stamp. It's no doubt fake.
But why would someone fake it?
If you're going to put fake stamps on a milsurp, generally people put recognizable stamps with a known history associated with the firearm, as a way of increasing value.
There was a lot of strange goings on behind the iron curtain back then, and we still only know a fraction of what went on with the mobility of their arms.
We know that Poland was using the SVT's, at least for training purposes, into the 60's, and were refurbishing the bayonets, even making new ones, well into the 50's. Is it really that much of a stretch to contemplate that they had, at least on a small scale, a refurbishment program for some of the guns?
Can I prove it either way? No. But I wouldn't discount the possibility out of hand.