I think one of the most eye-catching details of the Albini bookcase are the tapered blocks that form the feet and mounting points for the 4 vertical slats per upright (I'm going to call the top ones feet, too.) and their wide round pressure pads.
From viewing lots of images online, one foot has a single set of mounting holes for the slats, fixing their position so the end of the slat lines up with the start of the taper:
The foot on the opposite end is longer and has a series of mounting holes that provide gross adjustment of the overall length of the upright. In most photos I found, this foot was placed at the ceiling end:
I'll build the uprights from the same batch of cherry I used for my Z-chair. The wood was gifted to me by my brother-in-law a number of years back, and I have enough left for this project.
I made my best guess at the dimensions and angles, modeled vectors for the central section of the feet, machined some blanks to the desired thickness, and cut out the four feet on the CNC. I included a shallow dado on each face to accept the side pieces, which I'll cut at a later time.
The tips of the feet have a hole to receive a threaded coupler that will be epoxied in place later as well. A wood clamp was sufficient to keep the shorter feet in position for drilling, but the longer feet needed some extra bracing to keep them perfectly vertical. The holes were drilled deep enough so that when the threaded coupler is seated, it will protrude slightly from the hole.
To avoid the risk of splitting the cherry with a tight-fitting threaded coupler, I filed down all of the the corners.
The pads for the feet were a bit of a compromise. I was not able to locate any leveling pads that were quite like those on the Albini bookcase. I got something similar on Amazon, but they're a bit more utilitarian looking. Perhaps in the future I'll develop some lathe skills and turn some pads that are more sleek. For now, I'll use these. Maybe I can fashion some kind of sleeve that will cover the threaded part. Can you paint bolts?
I've painted bolt heads before - not so sure about threads.
I stripped the original plating off with a soaking in a strong citric acid solution (the kind used in kitchens). Then primed and painted. The result is a fairly robust finish.