I would start by using a feeler gage to check for gaps between the ways .001 or .0015 . Then move the cross slide off the saddle and Mike (Micrometer) the cross-slide ways front and back. If that is OK then move the cross-slide far enough back and set a .750" gage block on the headstock and tailstock side of the saddle top and crank the saddle forward and back moving the gage block. It should tell you what side is off. The saddle or the cross-slide. The real issue you might have is if you drill holes from the compound off your tool holder. Check it out and lets discuss it. My student Stefan Gottswinter has a good set of videos. He had a good teacher. Lets find out where the problem is before we decide to scrape it.
Good video. I recall Stefan saying somewhere that he had bought a commodity $ 500 Asian mini-lathe, and took it completely apart and re-assembled it while doing all the missing fitting and scraping, yielding a pretty good little lathe. After quite a lot of sweat equity. Did he ever do a video on that? I could not find such a video.