Lyman Plains .58 cal, Need help identifying

[gearchecker]

My F-I-L asked me to help him sell one of his BP rifles, but I can't find any info on it.
I'll post some pics for better identification.
This is what I know about it. I'm going to assume it's a Plains model. It was purchased in Tucson back in 1975.
Lyman .58 caliber. 29" Barrel.
Double set trigger.
Percussion cap.
It has a fully adjustable rear sight set. The sights are much like a target sight on a pistol.
Any help you can give to me is greatly appreciated
Gregory

Here are the pics.

 

[Chawbaccer]

See the big "I", that is an Investarms.

 

[frontiergander]

yeah this is basically the lyman trade rifle. I'd put about a $250 price tag on it. They pop up from time to time.

 

[mykeal]

The Trade Rifle is the closest - it has a single trigger with a 28" barrel in either .50 or .54 and a single wedge; it's actually an Investarms Hawken sold/distributed by Lyman.

Investarms makes all the Lyman guns.

$300 in good to very good condition, as much as $400 in new condition. The caliber (.58) brings a premium.

 

[frontiergander]

you do have to decrease a good deal $$ due to the sapwood on the forearm of the rifle. $250 easily out the door IMO.