Any Input On These Old 3c Washingtons Appreciated

I'm an amateur with this issue & know very little about the Plating & colors. I have these 3 covers I would like some input about. The perforated stamp looks like it is a 26 (frame lines continue). The cover w/ blue cancel has an imperf TI, but I don't know if it's a 10 or 11.

The third cover is the one I'm most interested in. It has an imperf TII, but again I can't tell if it's a 10A or 11A. The impression is incredibly clear & crisp. There is a small dot below LR triangle (if that helps). Also the cover came with a couple small pencil notations "Unadilla NY, 1852' 1L & UL triangle"(looks like 1 line recut to me). I don't know if this is suggesting "experimental orange brown, 1851-52, Plate 1L?

Thanks a bunch!

The third one is an 11A, plate 1L, position 29L. Many of the 1852 brownish carmine stamps have a rich deep color and clear impression like this one. Attractive stamp despite being cut in a bit at the bottom.

The other two are 26 and 11. I don't see anything noteworthy about either one, but maybe somebody else will spot something.

I also think the Plate 1L stamp is nice despite being cut into. Mr. Treen didn't directly decipher the notation but it is saying that it is an 1852 usage and the stamp has one line recut in the upper left triangle. There isn't anything that makes me think that it is in the experimental orange brown shade.

Thank you both, for the very helpful information! The covers were included in a lot I acquired a while back. The Plate 1L stamp stood out to me, because of the incredible crisp printing & color. I had my doubts that it was the experimental orange brown color; looked too reddish/carmine brown.

Guess I better stick to 1c Franklin stamps for now! Maybe someday I'll navigate my obsession towards this issue!