Started in Taiwan I think. Made all sorts of investment cast bits & pieces including cycle lugs etc. Worked closely with Tange who recently bought out the cycle parts of the buisness and transferred the tooling to their own factory.
I have been trying to solve this mystery myself as I have an 83 Raleigh SBDU 753 frame that has a seat lug with a web on the underside and have found one the same with the SR logo. I have spoken to the supplier who said they are Italian but can't remember the name.
Long Shen were distributed by Ceeway and I have a catalogue with lots of their designs for lugs etc. A large range but, as the catalogue is 'last century', I couldn't be sure that they are all still available.