It's not 4K, but many years ago, we ran 480i sources into a Holo3Dgraph card in a hptc, and scaled to 1080P on a 9" crt pj, on a 8' wide screen, with very nice results.
My question would what outputs does the laserdisc offer? The H3D card gave us one s-video input, one composite or one SDI input, and one component.
240i composite was far better then I would have imagined, considering the 96" wide screen. Most people would be thrilled with 480i component and 480i via SDI, was stunning.