If you really want that variety you should graft it.

A seedling will probably be somewhat similar, but waiting 9 years to find out you have a mediocre plum is a waste of life.

I can't identify it. ID is a very specialized skill. You could try to bring some to the budding clinic next year, or to the All About Fruit SHow if you freeze them until then.
John S
PDX OR

…that description sounds to me like a typical ‘flowering street plum’ I’d eaten thousands of as a meter reader. I’m sure there are various cultivators. My first thought was a “Nichols plum,” once promoted by the Nichol's Nursery …here’s mine: http://i206.photobucket.com/albums/bb12 ... /35043.jpg My Nichole’s plums are around two inches in diameter, and the ripening dates are very similar… In fact, with your description of the tree and fruit – I'd order a Nichole’s plum -- then graft a branch or two of yours to it… I suspect you’d prefer the Nichole’s… if so, prune accordingly.

And John’s right, likely the best way (for home orchardist’s) to propagate it is to take cuttings in January and graft next spring. You could bring your cuttings to the Home Orchard Society’s Propagation Fair in March, purchase the appropriate rootstock, and for a nominal fee have one of our grafters put it together for you (as many as you like), or of course graft it yourself.

I wouldn’t trust seed… not only is it a bit of a gamble as to how true it would be to the parent, as described, waiting for the eventual tree would be a short eternity… Grafting to rootstock would likely have plumbs on year 3 or 4. Grafting to a young or existing tree could be as soon as 2 years. Also, I’d suggest grafting on a pollinator of some sort… which with an unknown plum is a bit of a gamble.