Hi Alastair,
So far, I have personally been unable to confirm a separation by UV between pre- and post-war weights by either Paul or Salvador.
Some people say that under the longwave UV, the pre-war glass shows a "bright yellow-green" whereas post-war it is a less bright green with little hint of yellow. I don't now whether this would line up with your description of a "strong green" (which is a term I have heard used by others as well).
I have seen what appeared to be a "bright yellow-green" for some of Paul's weights that have really clear glass (i.e. no "darkness" as is usually said for his 1930s weights), Those weights have compared well to others with a Monart Glass label (which I believe were from the late 40s or 50s).
I have also seen the same longwave UV result ("bright yellow green") from probable Salvador weights that have regular visual features that are seen in known pieces from the Ysart Brothers period - particularly relevant are the rough-ground bases.
This is an area that I need to re-examine now that I have a few more examples. One day (as yet, I have no idea when) I wil try to photograph the longwave result for all of my Ysart weights under properly identical conditions. That should elimimnate any problems I have with variable ambient light and also any variability in the colour reception of my eyes / brain. And I would like to do that same excercise with weights that people say are pre-war because of the "bright yellow-green" (but that may not be so easy to organise!)
For the shortwave result all I have seen for early Ysart weights (pre-1956 Vasart and pre-Caithness Paul) is a dusty and muted grey colour.
For my "catherine wheel" weight, I get a "bright yellow-green" and "dusty grey" reaction.
So, Alastair, is the shortwave result for your weight actually a green and not a grey? That seems unusual, as does the "pale insipid" part of the descripition. Most intriguing!