Another point in favour of early Perthshire Paperweights is the number of spokes - 11 (also commented on by Derek, above). That was a regular number for many of the early PP1 & PP2 (and possibly PP6 as well??) designs. But the number of spokes in Perthshire Paperweights, Strathearn (and earlier Vasart Ltd, too) was very variable, so it's not a guaranteed identifier. However, the tidyness of this weight points, in my opinion, to Perhshire Paperweights rather than Strathearn.