need advice on ring repair

Hi,
I would really appreciate some advice on how to fix my great-
grandmother's ring
My mother replaced two stones with something the local jeweler could
find ("granat"? I think... ) when they fell out
some years ago, and now I am wearing the ring and... well, another
stone just fell out
I bought some (cheap) loose diamonds on ebay and discovered that they
don't match the ring at all.
The main problem is, the diamonds in my ring have a lot *fewer*
facets(?) and they don't have as much of that overwhelming sparkle,
they almost look _transparent_. They also don't have a flat top
(instead, they come to a point). The two fake "granat"replacement
stones do have a flat top (but they look different, and dull - I would
like to replace them too, actually). Here are some pictures (this was
really difficult to photograph... so please forgive the quality.. and
the background, lol) :
http://img.photobucket.com/albums/v5...olco/ring1.jpg
- the missing stone at 9 o'clock, the fake ones at 11 and 12. The e-
bay diamond is next to the ring, and the picture doesn't do it justice
to show just how out of place it looks next to the ring.
More pictures, from a different angle:
http://img.photobucket.com/albums/v5...olco/ring2.jpg
http://img.photobucket.com/albums/v5...olco/ring3.jpg
http://img.photobucket.com/albums/v5...olco/ring6.jpg - the
fakes are at 5&6 o'clock now.
http://img.photobucket.com/albums/v5...olco/ring8.jpg - at 11
and 12.

My main question is: where to get the right cut of diamond that
matches best? What is the name of the cut I need?
And once I get the right stones, can just about any jeweler at the
local Zales/Kay store at the mall put the stones in? I am kind of
skeptical, I've once had a necklace repaired there, and that was a
total hack job. Really terrible

And, finally, should I just stop wearing the ring (I like it, and I
would rather not!), since it's old and the stones are falling out?
What is the normal "lifespan" of a ring like this? This one was made
in 1880s.

Thanks!

P.S. if someone decides to reply by e-mail, please use "ochame_0
(at) yahoo.com", and not the address in the header (that one went
defunct ages ago).