Mick,
I'm biased. Keep the Raglan, unless (perhaps if) it is an early Mkl!
Def, for certain, retain it if is a 5". I'm reading here that it is a 5"and not a LJ. (Some describe any Raglan as a 5" lathe, even though it is a tad over that).
Lead screw only used for threading (don't know about the boxford). Delightful auto trip on long travel power feed apparently. The variable speed is good for changing cutting speed for chatter avoidance (but need an easy to fit rev counter for reproducibility – less than a tenner). You would regret moving it on, later. Built to a quality not to a price.
I would only change my LJ for a 5'', at my time in life and my (limited) use. Certainly not change it for anyting similar but made in China. It should be around long after many modern machines are dumped.