I had the same issue. In fact, I purchased one of these in .54 from a guy on line who mailed it to me loaded!!!! And with no tools. Got a tool from Midway USA. Don't see it there now but I believe the same tool is on Amazon--- Traditions Performance Firearms Muzzleloader Breech Plug & Nipple Wrench
https://www.amazon.com/Traditions-P...h+plug+wrench&qid=1561822897&s=gateway&sr=8-1
The larger end opening fit the breech plug on my .54. You can check with Pedersoli, they respond to you via customer service on their site, in English, usually in 2-3 days( I own 3 Pedersolis and have contacted them a number of times over the years) to make sure it is the same plug.
Now for the interesting part of the story with mine. It was frozen, and I mean frozen. And the breech plug was damaged from someone trying to get it out. Using the ramrod, I had determined that it was loaded. I used Kano KROIL Penetrating Oil, something that I have used on old cars for years. I and many others think that this is the best penetrating oil there is.
https://www.amazon.com/Kano-Kroil-P...eywords=kroll&qid=1561823254&s=gateway&sr=8-8
I was generous with it working from both ends of the plug. Leaving the barrel in a large bucket set on top of a bunch of lumber, or pointed up at the garage roof. I did not know if the oil might set off the powder charge. I was traveling a lot so I did this over a period of about three weeks. Barrel pointing down for a week or so, oiled a couple of times. Muzzle pointed up for a week, oiled a couple of times. And again, pointed down into the bucker and more Kroil oil a few times over another week. I then put the barrel in a huge vise. An old plumbers vise. THIS IS IMPORTANT. Don't do this with the typical vise. The ones you get today are Chinese crap and would not do well in this procedure (I know this from a few years ago!!). Maybe find a plumber or some shop that has a real vise made from real steel mounted solidly to a good bench, and one that will let you come in and use theirs for a few minutes.
Finally, I put leather on the barrel. And I used a small diameter steel pipe that slipped over the Traditions pin used to turn the tool. I did this to get more leverage. Then I tapped the pipe with a hammer. It came right out. Along with a black goo-- the old powder that was now saturated by the Kroil. I then tapped out a 405 grain lead bullet.
I looked on line and found some links on cleaning up rusted barrels. I was lucky as the bore was in good shape. I restored the gun, put a folding peep sight on it and more. Shoots great. Using lube on the plug, it comes out easily with the Traditions tool. Which in my case is the right length and seems to be made for this rifle.
I hope this helps and good luck. Pedersoli rifles are great guns and the inlines are relatively fast twist. If yours is a .50 it will be a 1-24 twist. I believe the 54 is 1-26. With the right bullets and charges, they are more accurate than my Thompson Encore.
This all reminds me that I should order a new plug from Pedersoli. Just to have one that isn't gouged up by the previous owner.