I don't think much is known about it. It was originally collected from a northern California foothill cemetery.
A group of us visited the original rose a couple of years ago. It was showing signs of decline, growing in deep shade and amounted to only a few scraggly branches. (no care or irrigation and in the middle of a prolonged drought). Not recognizable as any particular rose.
I haven't grown it myself, but have observed it at the San Jose Heritage Rose Garden. It is a nice compact rose from what I can tell.

I've had Romaggi Plot Bourbon since October 2009 and it's been a very slow grower for me. It's had very little disease and I like the delicate blooms, but there are only a few at a time, quite unlike yours. My poor soil and the drought might explain some of the difference.

I just went out to measure my plant and it's 30 inches tall and 18 inches wide, with one open bloom and two buds. I'm going to give this rose some extra TLC because it's well worth keeping and looks charming even with only a few of its lovely cupped blooms. I would so love to see a picture of yours, jasper. It sounds wonderful.

SdlM keeps on growing, but another one of my Bourbons, Mme. Dore, is even shorter than RPB, and also a shy bloomer, and it's about the same age as RPB. My only other Bourbon, Mme. Cornelissen, is taller but not nearly as bushy and floriferous as SdlM, which is still my best rose.

Ingrid

Wow very interesting to hear for a warm zone bourbon

Ingrid, I will try to get a picture of RPB in the next couple days. We are supposed to get rain tomorrow so will probably wait until after that. Maybe I can get out and take a picture before going to work this afternoon.

It is a beautiful rose. I also have Mme Dore but she has not performed nearly as well as RPB. Maybe it's location, as I have RPB planted in the front where she gets plenty of sun and not much shade. My roses generaly do better in those circumstances, even with our horrid heat. Funny, itsn't it? Actually all my best performing roses are in the front of the house, which gets southern exposure.

I do have good soil here, though, something like soil form the alluvial plain of the Salt River which used to go by around here but is now dammed up. I have clay soil but pretty nice, overall.

I would kill for alluvial soil! Unfortunately we have to deal with what we're given, and I envy those who are more fortunate. I'll be looking forward to the picture of your RPB.

We've been having a bit of rain too and tomorrow the snow level is supposed to go down to 1500 feet. We're at just over 1700 feet so it should be interesting.

Ingrid