Hi Roger,
Not an easy task. Just to give you an idea of the enormity of it, check
the following:
http://www.penpages.psu.edu/penpages...1/2940148.html
You may get some ideas from this site. If you had known earlier, you
could have
taken a branch from the dying tree and grafted it to a healthy plum
rootstock. If your tree was not grafted originally and you see some
suckers coming out of the base of
the old tree, you might try and propagate them, but success if
questionable.
Try your local botanic garden or library for reference books. I use
the 'Nut, Fruit,
and Berry Inventory Book', but is has no pictures. You may be able to
match it up
from the text descriptions.

Sherwin Dubren

Roger wrote:

Hello.. I live on the Central coast of california. I HAD a really
great plum tree which had a deep dark purple skin with a dark purple
flesh. This tree was old and the base rotted and about a year ago it
died. I would like to get this same plum variety, but now I'm not even
sure what variety it was. The leaves on the tree were also a purplish
color. Anywhere online have photos of plum tree varieties? I miss it..
any help would be greatly appreciated. thank you... roger