Thanks for the advice. I'm not making a business of this but these
ovens are simply too clean to dump. They only lack
warranty cards, etc. In fact some are still in (open) boxes. Built in
2004, the Panasonic model number is NN-T774SF which is
the inverter type (no heavy transformer), 1.6 cube, 1200W, SS finish.
The magnetrons are definitely failed as I can see
the magnets are cracked into 2 or 3 segments. The bad ovens work with
magnetrons from known good ovens.
The label on the magnetrons say Samsung OM75PI(21), I come up with a
Panasonic cross ref of 2M261-M32J.
I feel lower power, perhaps 1000W, will be far more reliable.

Since we all know new microwaves are so cheap as to be considered not
worth repairing, I'm hoping to find someone that
realizes even $44 is too much these days for most ovens. (My ovens have
$99 retail stickers on them) The mags and ovens are not likely to go up
in value. Some need glass plates which also brings my costs up. I
recognize I will end up keeping a couple of ovens for parts. Two units
are flawed cosmetically a bit too much.

As I said, I'm not in the microwave business and can hardly expect to
get much for ovens with no papers, box etc. but regardless
these ovens are just too good to ignore and dump. I took one(working
oven) for myself, one for my partner, gave one to my
wifes school and expect to donate the others as well. I'll find good
homes for them but only if I can find some used magnetrons
that will fit with a little reasonable, safe mod work (which I can do).
I can supply pics and measurements of the magnetrons
if anyone is interested in making a deal for mags they feel they will
never sell otherwise.

Thanks,
Dennis