What rifle do I have?

[wco]

I was given a rifle but need to find a part for it, so I figured I needed to know exactly what I had first. Sorry, no photos. You'll have to make a mental image.
It's a 45 cal percussion sidelock. 28 inch octogon barrel with half stock. Double set triggers with brass trigger guard. Brass patch box and butt plate. The markings simply say "cal 45", "Black powder only" and "Made in Italy". Plus there is a bold letter "I" inside a box.
Can you identify this rifle and where might I start looking for a fly for it?

WCO

 

[sundance44s]

What you have is a Hawken made by InvestArms of Italy ....I have one in 54 cal ...it`s a good round ball and buffalo bullet shooter ...bet you have a keeper ...mine is crome lined bore ...easy to clean too .
What parts are you needing .......Thompson parts fit mine ..So thats what I`ve used ....This rifle is a copy of a Thompson lock and triggers .

 

[wco]

Thanks Sundance,
I ordered a Thompson fly and it fit perfectly and worked great. Thanks for the info.
WCO