My opinion is that it looks like the top has been ground down. Look at all the edges ... they have a sharpness to them. But, it looks like a real TSVVS ... just made to be number one from some other number to make it more important and make extra money.
I share Bill's opinion. The cover looks as if "brushed". And the "corner" of the cover seems rounded, not straight. The rounded ones would be rather on 1950 TSVVS. See our discussion:
I agree with Bill. It really seems to be ground down. I have seen such tops by faked FED-Zorki. BUT even if it is NOT, I think it is not the price to try your luck for .