Also check out this thread: http://originaltrilogy.com/topic/Star-Wars-GOUT-in-HD-using-super-resolution-algorithm/id/17552

which contains some scripts (very slow ones!) that do a nice job with Video Enhancer’s AviSynth plugin. They also sell a stand alone app that works pretty well (and you get the plugin free when you buy it). http://www.infognition.com/videoenhancer/

Personally, I use Red Giant Shooter Suite’s “Instant 4K” for most of my upscaling in After Effects. It’s real easy - just resize he composition to the size you want, drop the effect on and boom. Instant 720p/1080p/UHD. Just remember to set the quality to “Best” before rendering. https://www.redgiant.com/products/instant-4k/