Not really, I agree with you Brian.
The Webley Service Mk2 series II did well, but it looks like a cracking example.
Prices/demand for the more common Giffard CO2 rifles appear to have taken a beating, but an awful lot seem to have been up for sale recently. I keep thinking of something DT Fletcher said a while ago about them having been impractical to refill when new, which might explain why so many look like they've spent the last 100 years in the back of the cabinet... Looks like he might have a point.
Probably the Titan looks the best value on your list, although it was refinished.