RickAZ,
If your rifle is a #1s model, - 22" barrel with Alexander Henry forend, - your rifle should have iron sights from the factory.
I'd suggest trying what you have, before putting out the money for a peep sight.
The reason ------------ Well, when I bought the my #1s - 45/70 I fully intended to scope the rifle, but before I got the scope in hand, I thought I may as well shoot the rifle with the irons as a possible back up.
OUCH!!!!!!!!!!!!!!!!!!!!!!!!!!!!! to the max! Because of the low head position required to use the irons, the same as would be required with a peep, the rifle beat my face to the point I wondered if I was going to be "man enough" to continue shooting it.
The loads were NOT high end wall banger loads, the boolit was an RCBS 405gr cast.
Thankfully I went ahead and mounted the scope and suddenly shooting the rifle was a totally different and better thing.
The higher head position prevents the pain which was extremely evident when trying the iron sights.
Having now hunted with the 45/70 and cast boolits for three seasons, the scope is, for me, the only way to go and that would still be true even if the iron sights would have worked.
This is a hunting rifle, and for that, I like glass on my rifles.
Crusty Deary Ol'Coot