Between the 9" & the 10K, the beds themselves are sort of more or less interchangeable. Subject to back drive or undermount differences and cut-outs in the bed casting. Some feet are different heights &/or have slightly different bolt hole centers, and some are machined to take the twist adjuster mechanism at the TS end while others are not.
However, if you research how often this topic or similar comes up, the components on top of the bed do not automatically set on a different bed without needing to be re-scraped. The headstock will probably re-align reasonably well - there is no wear on the mounting surfaces in use. It may tilt a little one way or the other sideways, which is practically transparent with an adjustable TS. It should be checked and scraped if necessary for longitudinal parallel alignment both ways or it will not be possible to turn or bore work held only in the spindle (no TS or steady rest) without taper.
If the bed they came off of had wear; the carriage, apron, and TS will have even more wear, and will need to be re-scraped to fit and recover original alignments on any other bed. If not, the carriage will wander and float on the new bed and it will be difficult to attain good finishes or predictable part geometry in the work. The TS will most likely need shimmed, as well. TS's wear at the front and gradually point down, often quite a lot. So the base needs scraped to make the spindle parallel to the bed, and to the headstock spindle axis of rotation. Then shimmed back up to height of the headstock spindle centerline. If it is not properly refit, drilling with the TS will fight the spindle center. In extreme cases, for work held between centers, it may be difficult to turn without a taper.
smt
