sorry Im hopeless with links but see if you can find Tony Treadwell's book Vintage English Shotguns and their restoration.
It was available as a PDF download - that's how I got mine and its a great read with detailed instructions on barrel browning from a person who taught himself.
Ive tried following his recipe twice so far - once with great results and once definitely so so I couldn't get the finish glossy and smooth it seemed to bite too deeply into the metal.
Sadly he died soon after publication; a lot of members on this site knew him
