Thank for the advice ,Ron.I used to work at BGM Colour Labs here in Toronto and we used to get slide film in GAF 35 mm cassettes which were reloadable.But the odd one would come through with GAF film in it When we ran it through our E-4 dip and dunk, the emulsion came off and draped itself over the following hangers ruining that film
Doug
When I was a kid, 1060's Ansco/Gaf Colour slide was touted as being very Home process friendly. GAF made a 16oz kit for home processing and mentioned the low temperature and relatively loose temperature requirements.
They also had a small gizmo called an "easy Loader" which had 5 lengths of 20 exposure colour slide film and came with empty red Ansco chrome cassettes, so you could have the fun of "spooling your own film".
One of the saddest times when I was working at Eatons Camera department was when a young lad picked up his blank film, he has loaded tri-x in a Anscochrome cassette as they were plentiful at the time, and just stuck a small dymo label to say it was Tri-x. The lab we used was proud of there 24 hour slide service, and so not noticing the label sent the nice red cassette with all the other nice red cassettes to the anscochrome reversal line. You could just see a hint of an image on the poor lads film, probably some contamination in the developer allowed some dye to form.
I recall that Ansco packed in the towel rather than making a C-41 colour film.
As far as 40 year old 500 ISO film, even if it was frozen, the experiment would be more of an academic interest rather than expecting good results. at least it is black and white so you should be able to use your favourite current developer.