Wish I could locate a pub with silver cap have been on the search for 2 years, do you know where it came from?
The Danish Pipe Shop had 3 for sale a few months back, but the markup on them was too steep for me.
As far as the OPs questions go, I am big fan of the pub pipe, and currently own 3 in different finishes. The Oom Paul shape combined with the Peterson system is a great combination. I'm am thinking about putting together a 7 day set.
They do come with some drawbacks, as follows:
1. Standard Peterson sloppiness in system pipe construction. The stems might be a bit cockeyed, bowl drilling not perfectly centered, obvious fills, wonky blasts, etc. Nothing that affects functionality, just cosmetic items that generally are minor quirks. If you are OCD about these things, walk away.
2. My biggest peeve with them, is that they are generally all drilled high in the chamber, with the draft hole on the order of a 1/4 inch off the bottom of the bowl. I sent my first back to SP and asked them to check 6 others, and send me the one drilled closest to the chamber bottom. The one they sent had a draft hole that was basically the same distance off the the bottom, so that was a waste of time and money. I've resigned myself to mudding the bottoms, which is a PITA quite frankly.
3. Burnout/erosion above the draft hole is a real concern, due to the high drilling, the steep angle of the draught hole, and the propensity of the Oom Paul shape to hold a lot of heat in the pipe wall above the draft hole. I would recommend not removing the precarb from this area, and keeping an eye on the area until sufficient cake is developed. If you start to see early signs of cracking/erosion, recoat the area with something.
4. Be okay with breaking down the pipe midsmoke and swabing out the well. You don't want to dump ash with a wet well, and you will likely need to dump ash at some point given the depth of the chamber.
This might seem like a lot of drawbacks, but the Peterson system totally works for this pipe shape, especially if you have a penchant for being a wet smoker. The way pipe hugs the jaw, the length of smoke (2 to 3 hours), and the feel in the hand, makes the pipe the equivalent of a security blanket. After the kids are in bed, I find it's nice to spend the rest of the evening tucking into just one pipe, and not having to fiddle with dumping and reloading another pipe.