8/5/19:
(Above: Naturally finished lumber with the first coat of polyurethane in place.)
Building Summary: This morning was a lengthy one, therefore I will do my best to list all that I did in chronological order. I began by unfastening old cow-wood from the posts out in the beef cow field and then measured / cut replacement pieces and fastened them on in the old one’s stead. After that, I procured a sander from Madre as well as some Polycrylic wood finish / sealant. I used the former apparatus to clean the sides of the planks that I thought to bear the most character (more in commentary), and then brought that wood to the hay-barn where Padre had set me up a small station for applying finish*.
I soon opened the old polycrylic can that Madre had given me and found that it was not quite right (glops of unmixable material in the bottom), but fortunately Padre and Wag were visiting Sparr Farm Supply at the time and were able to procure me a small can of fresh polyurethane. They soon returned with the can, and I was able to quickly apply the first coat to the lumber. This was ensued by my venturing to Jacobhouse, putting away all the tools I had used thus far, sweeping the floor, and stretching paint tape around the places I will soon be priming (the bed’s border and the stainless/galvalume walls that surround the bathroom pedestal area). My final task for the morning was applying sprayfoam to the underside of the utility hole that Padre closed up while I was out in Colorado.
West side of freshly spray-foamed utility hole. 
East side of spray-foam job. Hopefully this will reduce the chance of snakes in Jacobhouse!
Commentary: Today’s primary event was taking down an cleaning up my ‘naturally finished lumber’ project. Even after constantly checking up on the wood over the past half-year, I was surprised by its smoothness whilst handling it. Padre was the one to point out that it actually was naturally finished, for neither the top nor bottom edge of the primary board required sanding** (the same going for both 2x4s). I did, however, end up running over the primary face with ultra-fine grit sandpaper to remove a bulk of the bovine hair-tufts and to take dislodge any miniature splinters.
Originally, I thought my sanding was going to detract from the natural finish caused by living leather. What I found, though, and what Padre and I both appreciated was how the sanding not only highlighted the grain of the wood but also brought out the characteristic markings of bovine interaction – namely chew marks and horn scratches. After sanding, I wiped the board down with damp paper towels to remove any remaining splinters, grease, and bovine hair, and then I coated it with the first layer of wood finish.
Between the sanding, the warm amber hue of oil-based polyurethane, and most importantly, the work*** of the cows themselves, I found the results thus far to be remarkable.
The bathroom pedestals prepared for priming. 
I’m not sure why I stretched out this paint tape. With the mattress in place, I will never see that portion of the bed or wall. 
These are the new boards I tacked up for natural finishing. 
The polyurethane station Padre set up for me in the hay barn. While I was painting on the finish, I could not help but remember that about one year ago, I was applying another form of oil-based solution to the front deck of Jacobhouse in almost exactly the same location.
Final Note: Later today, I will be applying the second coat of polyurethane to the naturally finished lumber, and I will likely add a final coat tomorrow morning. As for other morning activities, I believe there will be more priming and perhaps a return of the liquid turquoise.
*Chose the hay-barn for its draftiness and for its cover; I didn’t want any mischievous stormclouds to sully my silky smooth finish.
**Quite the feat, considering that the wood was originally quite splintery – a result of its being taken from Sparr Farm Supply’s discount lumber pile.
***I say ‘work’, but really, the boards I took down today are physical incarnations of bovine pleasure.