I'm not sure why you think the original is an issue.
Like I said. The command is greyed out. The originals are fine, and can play with a number of commercial codecs, and also with Quicktime. The issue has nothing to do with the presence or absence of the original file, it's to do with iPhotos ability to recognize or process the file type, more specifcally with the Library entry that was converted at the time of upgrade.
Associations at the OS level are fine. So it's either a library corruption for that type of file (ie; the conversion failed or the file type was not properly interpreted at the time of conversion.)
After some additional experimentation, I can successfully copy the files from the iPhoto library Masters to an external device, and re-import them with no issue. So it appears that something failed when the upgrade performed the Library conversion.
So there is a manual work around for this - but it's not what I would call a seamless upgrade. Very buggy release - iPhoto seems to have interpreted these file types as JPG during the upgrade.
And yes, I have done a few Library rebuilds, including thumbnail generation. I'll probably just nuke the whole Library and re-import the Masters.
But it's still a pain in the ***, and iPhoto still won't import from the camera directly without first copying the files to the local disk. So poor marks to Apple on this one sadly.
Thanks for your comments.