Yes my hammer is the cone but not very sharp of an angle
Maybe I will take it out and see if it shoots. last day of elk season I hunted all day with a musket cap on, and at the end of the day I was going to shoot into a target only to discover the cap did not go.
This picture might offer you a better look at Knight's Universal hammer.

Also the picture of the Breech Plug in your pic is probably a Bare 209 plug. There is a magnet in the bottom of the primer pocket to hold the primer in place. I would suggest a 209 capper to install the primer and you remove it with a finger nail.
The Red Plastic Jacket breech plug looks like this.

You need a Knight tool to install the RPJ on the nipple post and and the same tool will remove the the RPJ. In my opinion the RPJ is a safer method of ignition than the bare primer.
Personally I gave up on both of them and use #11
mag caps or RWS Dynamit Noble 1075
plus . With the #11 caps you can make the breech area virtually water proof with the right nipple installed.