We have another of these marks in our collection, the middle red mark, it is in another story 'L&Cie and ETS Chadelaud
Ets Chadelaud - Chadelaud Establishment - was a decorator of porcelain, they would have purchased their 'blank' pieces from various Limoges porcelain producers.
I know the Chaudelaud establishment was in Limoges in at 27 Rue Ampere in 1958 and then at 22 Rue Ampere from 1960. I have a hunch that this mark is probably from about the mid 60's but have no proof and I am still investigating. If you know anything about this gold 'Imperial Porcelaine' mark please do contact me, otherwise if I discover more pieces of the puzzle I will post them here. Send me an email from our contact us page if you would like to be kept informed of any progress I make.