Here is the current link, but don't be suprised when it doesn't work.
MUZZLELOADER BUILDERS SUPPLY
Last time I was there, they were just sitting it up and nothing was available.
To contact them call 479-292-8866 They are in Ozone Ark and they should be there between 9AM and 5PM.
The underhammer action Susie shows is not a machined assembly. The parts are as cast and consist of the Trigger Guard/Mainspring, Trigger, Hammer, Trigger bar (underside of assembly which the hammer and trigger mount on) and Tang/Reciever (part which barrel breech fits and top strap (or tang).
The 2006 Catalog says:
"I didn't know exactly where to put this contraption! Ever been out to the muzzleloading range and hear someone holler "Underhammer!"? Will, this is it! This is the parts list you need to build one of the easiest rifle assemblies that can be made! This trigger and tang assembly includes all of the as-cast parts required to build your own underhammer rifle. The tang is cast with a .740 diameter hole for the shaft end of your cyinder breach plug. The trigger guard is the spring on this system. Kit includes tang cast into the reciecer, trigger bar, hammer, trigger and trigger guard spring."
Order number 36530 $60.00
By the way, the E-Mail links to many of the suppliers are available on this forum.
Go to the main menu and in the General Muzzleloading section find "muzzleloading links". It has a picture of a Lynx. Go to "Suppliers, Parts & Molds Links" down towards the bottom. After clicking it then go down to the bottom of the page to find PARTS.
Up at the top of the page is a bunch of SUPPLIERS which is also real handy to have available.
You can thank ole Musketman for putting that area together for us.