Finished plotting all stars within 50 LY, just shy of 800! Started work on linking the arms. The "American" arm is the easiest to start with, as the other two have some potentially overlapping territory.
Hard to see detail at this scale, but I decided that any star within K2 and F8 of a decent age could be a habitable world candidate, and drew strong lines from Earth to those systems. Anything else is a secondary dotted-line path. You can kind of see that in the cluster around 61 Cygni and up by Gliese 660. If you're more open minded about red dwarfs hosting garden worlds, then you'd have to revise the lines a bit.
Stars are color coded based on an article I found about the actual color of stars. The dark red is for brown dwarfs.
The arm ends at Upsilon Andromedae, which looks like it might be just old enough to host a pre-garden world. If you're cool with a 165 LY journey that is. 28 segments, probably a 1-day stop at each to discharge. Hitch a ride on an Anjou and it would probably take more than 7 months! If I were going to create my own home-brew 2300 alternative, I'd probably say anything past Sigma Draconis is unexplored, and leave those stars for intrepid characters to investigate.
This map can't get to Zeta Herculis like EDG's map does, because a connecting star on his map is farther away than 50 LY! I ran into a couple spots on the map where that happens.
And of course I'm curious to see if Gaia has found any new stars that might bridge some gaps and create new fingers.