All I can give you is some basic info.
John Boulton had been an engineer who founded the enterprise by his name sometime in the '70s. His target market was the super wealthy and the firm specialized in the maufacture and installation of residential "sound systems" with multiple speakers throughout the home. Electronics and particularly the speakers were intended as permament fixtures- built into walls/ceilings - normally during construction. The systems usually had a number of telephone-style keypads located throughout the home for remote control in a variety or areas.
Boulton equipment was extremely expensive. I once read an invoice totalling in the multiple $10,000s for an installation.
Boulton rather enjoyed the high life himself and constructed a mammoth house, with all exterior facades entirely made of glass. Sometime in the mid-'80s, Boulton ran into financial difficulties due to his profligate spending/lifestyle and the company he founded was put into receivership. I'm not even sure if construction of the "glass house" had ever been completed when everything came to an end.
My only direct experience with Boulton gear was at the parents' home of a high school friend. I remember the system sounded quite good - especially for a "built-in". However, I also remember it broke down quite a bit. If you do a search you'll be able to find some info on Boulton "Signature Series" equipment, the company and a pic of the big "glass house". Within the last year or so, I found an unused & uninstalled Boulton sound system on eBay- along with invoices for huge money (circa 1985 when the troubles began). It brought very little money.