Thanks. For the two posts above, will these damage (destructive edit) the compressed .jpg data, at all?
if you assign a color profile then the image data values are unchanged, you just changed the terms of refernce in lab values.
if you convert to a different profile the image data is irreversably changed
if you have 'thousands' then you should consider using something like a gmg colorserver which can accuratly process bulk archives
this will cope with mixed profiles within the archive
you could get this done as a service
if you can get samples with embedded profiles then those profiles can be extracted and used to convert images known to be in that colour space but without embedded profile