Hi Cassidon, I think you've got a littel confused in your post but I think I know what you may be after! Etro are just Etro the family who own and operate Etro aren't involved with other brands but they do produce nice shirts.
Are you thinking of Angelo Gallasso who is the creative Director at Billionaire Couture but also involved with Eterno which were formally Interno 8 clothing? He is the one who does wing tipped over-pronounced collars and cocktail cuffs etc. The Eterno shop is in Conduit Street not far down from Yohji shop. New collections are arriving now they do bespoke as well, they do some suits and overcoats as well made with Loro Piana fabric, an absolute giveaway at the prices they are.
Forgot to add, website is
Eterno Index but no online ordering pay a visit to them if you're local.