Thanks for the opinions.
Lead, with a vintage instrument (even though not particularly valuable) I certainly would go to a professional luthier if I were contemplating anything more than changing the changeable bits. (Remember that the bridge on an archtop is not attached to the guitar.)
I've settled on a two piece (pretty much standard for archtops of the period) with a machined bone saddle. Cheap enough to toss if I don't like it, but it looks like the best acoustic coupling into the body I can get. It has a full contact bottom piece like the original, rather than the two-footed pedestal type that is common now.
And this particular guitar has a zero fret, so nut compensation is not practical.
I am going to try D'Addario XL Jazz Lights (.010) as a fair middle-of-the-road first shot. I prefer wound third strings as it seems to me the timbre transition between the wound fourth and plain third is too big.
BTW I am pretty handy and experienced with setup and minor mods/repairs. Just about the only thing I shy away from is flat-top neck resets, finishes, and valuable instruments. (I have a finish question I may put forward one day regarding a different guitar, if I ever gather the nerve to tackle it.)
Looking forward to taking delivery on my strings and bridge and disappearing into my study for a weekend.
Oh, and I was able to identify the pickup. It's a DeArmond Rhythm Chief, quite proper to the period of the guitar.
Thanks and happy fretting everyone
-Glenn