Just finished up restoring a Hellis that was the Spit of that gun, i similarly have an Armstrong and co which is technically and visually exceptionally similar side plates and all.
Website seems to be down but i researched hellis a bit and he definately did supply the trade - Except taken from the google listing but unfortunately the website may have disappeared which is a shame as they had a surprising amount of history on there.
Some of the Sales records of hellis are still in existence here in the UK. - however you wont glean anything from them other than the original purchaser and purchase price.
"G & S Holloway, S Wright & Sons, Harrison Brothers and Bentley & Playfair were ... of Norwich and Linsley of Leeds being two of their better-known customers."
James.
