CSR = Cristallerie de Saint-Remi seems a logical conclusion.
I found this:
Pierre Girre (1901-1990) ... in 1926 ... create(d) his own designs at Cristallerie de Saint-Remi (Sevres) under the pseudonym, Pierre d' Avesn.
The link to Sevres also explains the link to Etling, as mentioned in my initial post. Some Etling designs where reproduced by Sevres after Etling had ceased trading.
However, I am somewhat confused by the statement on the Scottish Antiques site which says:
Orreot was a brand name used by CSR.
.
Oreot (one 'r') exists and so does Oreor (apparently associated with Van Haeleweyck Frères, Brussels, Belgium), but not Orreot (two 'r's). Was this a typo? I am uncertain whether the vase referred to can be checked since it was sold by the dealer. Hartmann says Oreot is a French company making pressed glass vases since about 1920, but nothing more.
I will ask the dealer where this connection between CSR and the Orreot brand name came from.