Thanks for your patience, Robert.
I've attached a brf with my transcription of these 5 measures.
I would include a lengthy TN at the start (I'm sure you've got one going already!) to explain that the music is mostly unmeasured, and as such you will be aligning notes vertically to follow the print placement of chords and musical events within the measure. I would NOT add rests and attempt to figure out on which beat a chord would fall in an unmeasured piece like this.
So - in measure 1, I moved both footnote indicators to the start of the measure. Both hands have diamond shaped notes, so I indicated that in both parts. (I also fixed the first note of the left hand.) I aligned the notes vertically, along with their part-measure repetitions. Without some sort of alignment factor, the braille reader would not know that the diamond shaped whole notes and the diamond shaped quarter notes were to be played simultaneously. (I toyed with using coincidence signs, but the vertical alignment was better for the rest of the piece, so I went with that throughout.)
I left blank lines between parallels for clarity.
Measure 2 - I expanded the parallel to three lines and aligned the musical "events" vertically, using guide dots where necessary. For the wavy line that means "let die away", instead of using a footnote, I created a symbol which, set apart by blank cells, now means "let die away." I listed it in the SS list. As you'll see in measure 5, I use the same figure but lengthened it, to represent the longer wavy line. I think the vertical alignment of the chords is clearer that adding rests which don't really make sense in this rhythmically ambiguous piece.
Measure 3 - same as measure 2 basically.
Measure 4 - easy! Actually metered so it's quite straightforward. I decided vertical alignment was not necessary here, though it would certainly be ok to do so to maintain consistency.
Measure 5 - I used the x-shaped notehead to represent the knock symbol (and defined it in the SS list.) Even though we are still in 4/8 theoretically, I vertically aligned the events to make it very clear. I don't think added rests are needed. I divided the measure after the left hand knock. Notice the longer wavy line in the right hand.
Let me know what you think about these solutions. Also - could you let me know which piece this is? This would make a great bulletin article topic!