I believe Antoria was a UK brand - the guitars were Japanese, but had the Antoria brand name slapped on them specifically for export to the UK. In the late '70s/early '80s they were distributed in the UK by the same people who distributed Ibanez, and I've seen Antorias which looked very similar to Ibanez guitars from the same period.
Having said that, this could just be a bog-standard LP copy like the "Arbiter" one my parents bought me in 1980. It's very hard to know! It certainly looks pretty.
Antoria guitars were made in the Ibanez Japan factory for Coppocks of Leeds (UK). Just the same as CSL were made in the same factory for Charles Summerfield Ltd of Gateshead (UK).
They were both very accurate copies with great pickups (not BKPs of course... Maxon usually), build materials etc. Only difference was that the neck was set/ bolt-on, as opposed to Gibson who set/ glued in. I have quite a few of these Les Pauls in my collection. They all have the 'open book/ moustache' type headstock, which prompted the so called 'Lawsuit'.
Sound-wise there is a slightly more 'spanky' sound, but to be fair I think it's hard to hear a huge difference really.
Nowadays both brands have been re-issued and you can get a set/ glued-in Antoria LP copy and a Set/ glued-in LP Jr DC copy. Our shop is a stockist of both, they're quality items, made in Korea.