I believe this is a Paul Ysart weight and probably from the 1950s perod. I assume a couple of the under bidders also believe that. I will know for sure when it arrives.
Recently I bought a couple of other interesting weights that at first sight appeared to be one thing, then on closer examination, turned out to be something else. One looked as though it might be an early Ysart - and maybe even 1930s - but under UV it checks out as late Vasart or possibly Strathearn! The other was "clearly" an early Paul Ysart Harlequin, until various details showed that it was consistent with Salvador's working - it looks really good from a distance but close up there are things that show a lower quality not expected from Paul, and the base finishing confirms the identity.