1917 no.1 mk.3 markings

Its a "star in a circle" over "PSF", which is a post-1951 Italian proof mark issued by either Gardone or Brescia proof house.

I would concur with the Italian origins of the marking. Have seen similar recently.

That would fit with what I've been told by the dealer, thanks for all the replies

I meant to ask in my earlier post, what does the V mark on the knox form stand for ? I've googled it a few times and can't seem to find an answer
Thanks