7/26/19:
(Above: Aluminum angle stock* used as trim around Wall #5’s shelving.)
Building Summary: Today I began by neatening up the work bench so I could move it to Jacobhouse’s postern end. This was followed by my beginning to put up trim around the shelving areas on Closet-Wall. The task consisted of snipping/hammering back any galvalume that overlapped the plywood edge, taking measurements, cutting ¾” aluminum angle stock via hacksaw and aviation shears, making adjustments to that stock with additional cuts, reducing the length of the shelves themselves**, and then fastening the angle stock in place with rivets.
Commentary: It was a much better morning at Jacobhouse today. I got an additional hour of sleep by going to bed earlier, there was a pleasant Segway ride with Padre through the beef pasture (the first in three weeks), and this was all followed by some novel container home activity: trimming galvalume with aluminum angle-stock.
From an initial impression of the task, I would state that the most instrumental part of the procedure is making precise measurements. Once those measurements have been made, however, and once the aluminum has been marked, it is an easy matter of cutting the metal via hacksaw. Saying this, it seems that the task of cutting shall be made even simpler in the near future when I have access to the diamond-blade that Padre ordered off of Ebay. The blade is compatible with almost every type of circular saw, and I have a feeling that if I do as Padre suggested and place it on the miter saw***, it will make cutting the aluminum trim as simple as if not simpler than cutting the PVC trim for outside Wall #6.
As for additional highlights, there were two of rather mundane variety this morning, but they were appreciated all the same and shall be included as pictures below:
Up until this morning, the work bench’s primary purpose was to hold all of the various fasteners used in Jacobhouse. Now, however, with those miscellaneous screws and bolts removed to another location, I am able to use the table as a sturdy clamping surface – optimal for when cutting aluminum angle stock. 
This was the implement I used to file down some rough edges on the aluminum today. It was found in the cow feed, and Padre and I believe it to be a farrier’s rasp (basically a fingernail file for horses.)
Final Note: Tomorrow I plan on performing the same sort of activity as I did today, except I shall be doing so on the bedroom side of Closet-wall. Once the outer edges of the bedroom shelving have been trimmed, I may move on to the bathroom storage space, or I might go about painting the interior of the bedroom / bathroom closets… Though, if that’s the case, it may be beneficial to paint before I do any more trimming; that way, I would not have to lay down excessive amounts of painter’s tape.
*Though I would have chosen Aluminangle as the best term for this sort of material, the technical term for aluminum angle iron (or for any L-shaped metal) is “________ Angle Stock”, with “________” being the place where the metal’s name is inserted.
**Needed to do this so I did not have to knock a wedge into the wood or the angle-aluminum where one met the other. I ensured that I cut off enough so the other side would not experience the same problem.
***Alas, I just moved that heavy lummox of a machine up to the farm’s office. When the diamond blade arrives, though, it will be well worth bringing back out to Jacobhouse.