Made some slight headway:
1) sanded the boards with 80 grit paper – getting them even this smooth is a big improvement and makes the wood look so much nicer… makes me appreciate the poplar more.
2) jointed all the edges to bring the final width of everything down to 11.02”. Egads, that was awful – I started out at around 11-3/8 and was wanting to get it all down to 11-1/4, but my calipers got screwed up. It might have been all the sawdust in the air, but they were slipping and giving me incorrect readings. So one thing led to another and finaly i used common sense (which i should have done to start) and double checked every measurement by laying subsequent boards on top of each other and comparing the overlap. yikes. anyway, i ended up jointing about 3/8” off everything… around 25 linear feet. not so fun.
the good news is, my router table jointer system seems to work great! Everything but the 60+” boards was dead easy to do. The 60+ stuff could benefit from a longer table (currently something like 32” long) and a longer fence to go with it. But using an MDF fence with a cereal-box paperboard spacer on the outfeed is totally awesome.
the bad news is, i think some of the crosscuts are out of square – and i think it’s because I assumed that my rip cuts were perfectly straight, which they werent. So I might have to do a tiny bit more work there. But the good news is, only one side of each shelf-board counts (dado to side), since the other is just suspended at a point by the narrow side.
3) I decided on the finish: 2-3 coats of that antique oil stuff ( which i think is a wiping poly-boiled linseed mix) for everything and a 25%/75% combination of walnut/cherry stain for the narrow side member. The stain over 2 coats of the varnish was definitely an improvement over the bare wood – much much much more uniform.