Many thanks Carlos,
Suffice to say that I have 2 sig keys missing, IDs 8750d2c4 and 2e80fbc2. I can't find rpmkey rpms for them. I have found the keys and downloaded them. They load into Kgpg on the SuSE box without complaint. RPM ignores them after import - key IDs not listed in 'rpm -qa gpg-pubkey*'. Errors continue. Can't do apt dist-upgrade without turning off sig checking. Bad. :-{
Suposedly, you have to import them with:
rpm --import public-key-file.asc
as root. I don't think Kgpg will inport them to the proper place
I tried rpm --import. It didn't have any noticeable effect, nor did it produce any errors. I don't know what to try next ...
Then, the only thing you can try is (according to the man page):
rpm -qa gpg-pubkey*
I used this to confirm whether the keys had been imported. They hadn't. Other keys which had been retrieved by a similar method had been imported, though.