Of course SD laserdiscs are going to look like crap on a giant screen. The only reason for upscaling them is to bypass the terrible scalers found on many flat-panel TV's which turn SD content into a blocky mess.
We're doing this for the image content, not the image quality. Blending two or more discs won't perform miracles, but it could produce a result better than any one disc, maybe even better than the '97 SE or GOUT (with much stress on the "maybe" part).