Jo, the properties data I want to retain - for verification, etc. - were auto-embedded the moment I downloaded the images/files using my Mac. The were not bookmarks; the files embedded the originating URLs or full pathways the moment they were saved. Right now, the files are date/time stamped. That info. is what I do not want altered; it's essential.
Conversion is an issue if it means a loss of the critical data.
For screenshots or captures, I have figured it out:
It's...
Hit the key with the Apple icon (next to the spacebar) & print key + shift key and the numeral 3 key. It takes the shot, which can be opened in Simple Text or in pict view. It seems such a circuitous route for screenshots but the only way I've found to do so on older Mac Power PC.
I could upload the files to a hosting site, only, if downloaded by a PC, I have a hunch the properties will not reflect the same as with the Mac Power PC, which holds the URLs in place.
I've got this strong unwanted feeling right now that I am going to be spending more time than I wanted working on this, but... in the long-term, that's okay. I'll just have to pace since I'm working against exhaustion (which was not a factor when I was using the Mac and moved on). I just have to hold up my end at this point.
Too, I am thinking, maybe I can run a hash value on the older files, try conversion and see if the hash values are negatively effected. If so, just present the original files in Mac format... and do a walk-through.
I'm probably the only person I know who has never let go of a hard drive - because I do need for data to remain in its original format.
Gawd, I feel so much pressure.
I had stipulated less than a month time-frame for transfer of data (to an agency scheduled to do a pick-up an deliver); I understand now, the time-frame is too narrow. I likely need to consult with folks in forensics more savvy than I and push back the time-line. Nothing like working years and years on something, and knowing the data is in place but it has to be as "found" or it can be nuked in court. I never imagined this. So... I ain't gonna blow it on my end

.
Still, I'm gonna hope someone may have far better "guru" insights than I do. It will surely help.
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".... This world wasn't built for people in wheelchairs ...."
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