I recently wrote an editorial article which referenced several national (UK) reports. These are typically freely available as pdf files online via institutions like the British Medical Association, the General Medical Council and so on. They are not published articles in peer reviewed journals but are major and important pieces of work. When I referenced these reports in my editorial, I initially referenced them as online sources (with date accessed, date published and the URL where they are available from).
During the course of peer review and submitting to journals, one of the national reports (from 2015) disappeared from its URL which was not permanent. The organisation probably removed it as it was old. I had saved a pdf copy of the report. It was no longer easy to find a copy online and the one place I found it was not a professional website URL (just some person's blogging site or something like that).
My question is, to future-proof my article from reports like this disappearing from non-permanent URL, can (and should) I load my "hard copy" pdf into a repository and provide a permanent location to the report. This can be done with OSF, Zenodo etc and it would then be permanently available with a DOI.
Otherwise any URL cited can just be changed or the report can be made unavailable any time.
Alternatively, should I just leave the "date accessed" as an old date (from a time when the report could be accessed) and readers would understand than the reports might not be there in future?