Well if you still have the cs6 install discs then you can probably still install it. Alternatively there is piracy… I know it’s frowned upon but since adobe doesn’t even give you the option to legally purchase encore, would pirating the software be any different than downloading despecialized or the 4k## series? I guess it’s just a moral decision.
I would be of the opinion that yes, it’s almost a preservation. But there are a few issues the older Encore is not compatible with Win7 or Win10 so you’d have to reinstall XP which is also no longer supported. I’ll load up the old back up HD to see if I still have the install files for CS6 - I hated the learning curve so I stuck with TMPGenc simple but quick and easy but my menus did lack the WOW factor.