Absolutely worth restoring. 1948 would make it an early version series 60. Also listed as a 14", 16.5 actual, not too many of those around. By the time the series 60 migrated to series 61 there was not a 14".
Not a toolroom lathe though. No taper attachment, and no leadscrew reverse. Not a deal breaker, just pointing that out. Can still do really nice work.
Couldn't find specs, and your headstock speed chart is off. What's the spindle's top speed ?
The bed is no problem at all. Any working machine will end up with some dings. I'm guessing a work piece was thrown, due to its location away from chuck. The most important thing on way surface dings and bangs, is not to have a high spot. A high spot would dig into the surface of carriage or tail stock. Low and even surfaces will not. The bed is not cracked in half. The way surface took a shot, someone repaired it. You could fill what looks like a crack, but is a weld seam, with any sort of epoxy if your are concerned about fine debris gathering in it.
The clutch arm on apron is relativly easy to fix, and a common wear point on Monarchs. If only fixxing that you can leave apron on and that assembly un-bolts from bottom of apron. Remove leadscrew end bearing from tail stock side and slide it off. You need to make up inserts for that assembly. You can see what I did here at post #75, and probably a page or so prior to this post:
Monarch Series 61, Rebuilding for Improvement
In this same thread, page 6, post #115, is what I know about the leadscrew and drive gear on qcgb side. I did not take that fully apart. But it may be as simple as tightening nut to the left side of leadscrew's gear.
Some Vintage Machinery links you may have seen. One is a brochurefrom 1948, but no specs, but mentions a 14":
The pdf:
The 60 operators manual from 1956:
The pdf:
