Before the drywall was installed, I first installed 7/16 plywood 36" high that would be my nailing surface for the bead board wainscoting. Then I hung drywall on the remaining exposed walls. I had plenty of bead board, so I used it on the back of the pantry and built in shelving. Though I wasn't ready to add the bead boarding quite yet, I did have to install behind the radiators so they could be piped in before winter.
I swapped out the basement door with a correct style 5-panel that I trash picked (people still throw away solid pine and oak for hollow cardboard doors??!!) Next step was finally rebuilding the bottom steps that were hacked out when the butler stairs was walled off. The landing that the door jamb rests on had it's lip cut flush, so this involved carefully dismantling the jamb so the landing could be replaced. For material I was able to use the original heart pine plank sheathing I removed from the back addition. This stuff is hard as nails and will hold up to foot traffic no problem, and was the right dimensions to boot. A minor change from what was original, I extended the steps over another 6 inches and tied them into the built in pantry. Once completed the jamb was reinstalled, the door hung, and the butler stairs were back in action after 40 years.