We had a flat way lathe bed,can't remember the length,36"+? as "part" of our Tig welding station.It was just "OK".It was handy only by having tooling fixtures that slid on.Think specialized, repeatable fixturing on certain jobs that kept showing up.It had a 18", 3/4" thick round plate on it that slid.It was nice. Finally gave it away,keeping all the tooling.The guy is a blacksmith and fabricater,he uses it as a square stock spinner.
A mill table does the same thing,and more because of multiple tee slots.I got the lathe bed for free and if that's the case for OP,heck.... go for it.
Now,a smaller flat way lathe bed is a different story.The 6-18 craftsman's are nice because we can fixture on it,then move it to a mill or one of the big DP's not taking up real estate when not in use.A little small for welding on though.These are small enough to use in different planes.Good luck with your project.