Thank you, Anne - a star yet again! - and also thanks to Thomas Joyce, of course, for TNA corroboration.
Certainly very 'Cottle-ish', and presumably made in Czechoslovakia again.
I will add the RD number to the GMB RD Number Database on the Glass gallery asap.
I will also put links to this thread on the other two GMB discussions to which I have alluded.
Fred.