I have found that two makes of pipes work best for me. They look good, are comfortable, and smoke like nobody's business. Every one of them. So I got rid of all the others, minus a travel pipe or two, and will only buy those two makes now.
Interesting. I've never seen the "R" stamp. Also, why are you positive the stem is original? Sasieni inserted rods to create the dots, so they won't buff off.
Nora Jones
Diana Krall
Susan Tedeschi
Holly Dunn
Patsy Cline
Linda Ronstadt
Cheryl Crow
Gretchen Wilson
Carrie Underwood
Joan Baez
Joan Jett
Dolly Parton
Hurricane (Band of Heathens), Nose On The Grindstone (Tyler Childers), Pocket Full of Misery (Uncle Lucius), Ballad of a Prodigal Son ( Lincoln Durham)
I'm not sure where you are getting your information. There were patent numbers on both US and European pipes. The numbers were different for the US. The patent referred to the stinger, not the dot. Dunhill had a patent on the dot, which is why One Dots lasted in Europe longer than the US.
To simply look at, I like them all. As far as smoking, I only smoke straight Billiards, 1/8 bent oval shank Brandies, and CLASSIC straight Dublins, you know, the ones with slight expansion of the bowls. Almost, but not quite, Billiards.