Mike, you're as bad as Slemmer. Can't you wait 'til I get to those items in the list before you go posting pics out of sequence? So, I'll tackle the remainder here and now.
Numbers 22-28 --
#22, 23: I personally don't think these are intentional marks. I'd suspect that the "I" is a portion of another stamp, probably and "L". I think the same of the "V". I really don't know what to make of Mike's first pic...if it is indeed insized as Dave suggests, then it is not original. The second "V" pic is a fired bullet and is probably a deformed "L".
#24: I think the "shield" shape found in an Enfield base is just a distortion of the "triangle" in fired bullets I already discussed further up in the thread.
#25: This raised dot is found in many bullets. In cast bullets it was an attempt to eliminate the air bubbles that formed in the cavity. In pressed bullets it is found in different sizes and is from an unknown maker.
#26, 27, 28: Not real as far as I'm concerned. The "CS" "US" and a supposed "GA" are claimed to exist. Why? Who would have made them? And why would a die be engraved, and all the work involved, to only have one bullet be produced? Without naming names, the story I've heard was that a certain dealer (now deceased) used a heated metal stamp to form these marks in the cavities of original excavated bullets.