Agfachrome 100 Development Process?

I've tried all the usual search tools but have failed. I discovered an exposed roll of Agfachrome 100 slide film, and was trying to find out if it could be processed with E-6. Other than "Agfachrome 100", the canister is devoid of any other branding. It does say, PRICE INCLUDES PROCESSING, SLIDES RETURNED HIGH IN QUALITY PLASTIC MOUNTS. I was a heavy consumer of Agfachrome in the 80's, but never paid attention to the processing method. I haven't the slightest knowledge of when this was exposed. Here's the canister, even image search failed to pull back this one:

As it marked ASA and from the early 70s (?) I I think it was the older forerunner also made by ANSCO and GAF was very different more like E 4 and required a reexposure during the processing under a very bright light. ASA changed to ISO about the same time 1974 or so as E 6 was introduced.

.It looks like the very nice film that required a specific, Agfa only process.
Not E6, and not E4, although probably closer to the latter.
The bad news is that you won't be able to use it as intended and get it processed.
The good news is that the cassettes are great - I use them as reloadable cassettes for my bulk load film.