Hi,
The rifle you are speaking of, is a Hopkins & Allen model, made by Numrich Arms, out of West Hurley, NY state neary Albany, NY.
They were made from the early 1960's, on into the 1970's
Most calibers were .45, but shot a .440 ball best.
They were many models made from Buggy rifles to heavier, long barreled rifles.
Apparently there were a few .50 cal. models also, but best of all was their .36 cal..
All models used a flat spring for the trigger guard, but also powered the hammer ( great system)
Maybe not the prettiest, in yhe rack, but will ou-shoot any rifle( perhaps most).
The only way to take apart is to remove a pin that holds the barrel to the action, but there is no real need to do so,( better to leave it alone)
I do hope this helps.
Old Ford