That Mercury looks like one sweet ride.
Once you back off the pace a little, these bikes are fine for longer days. I just rebuilt a 3 speed 1950 Norman together that was used extensively for touring in the 50s and early 60s. This was with an 18t rear cog and lots of pushing up hills. Much easier with a 22t.
I also prefer the FWs or S5s. The 4 speeds are cleaner with only one shifter and cable. But the 5 speeds are much less finicky, and parts are easy to find.
If anyone coming to this weekend's ABCE knows of any smaller guys who might want a 3 speed, I've got a rare 19" Men's Frame 1958 Robin Hood that I'd like to get $30 for. Needs work but the frame is good. Call me at 612-824-2372 if you are interested. I have fenders and chainguard for it. And I'll throw in a very low mileage womans frame, Raleigh built, 1965 Huffy for parts.
BTW I'll be bringing
cotter pin presses and 22t cogs to the swap meet.