Switzerland Seated Helvetia 2c - Different Stamps?

Are these intentionally different, with different catalog numbers, or is one of them worn and that's why it looks like smeared letters?

Left stamp with clearer letters is Scott 60 bister on granite paper
Right stamp is likely scott 52 buster brown on white wove paper

My stamps show exact differences as yours

Thank you very much. After going over big blue, stamp collecting world (SCW), stampworld, Scott general, and SG general, I see that there were 3 major issuing dates: 1862, 1867, 1881.
SG 2014 only mentions the first one, so doesn't help here;
SCW doesn't show any visible difference in the letters and numbers;
In stampworld slightly, and in big blue more notably, there's a difference between the first set and the other two.
Can it be that the right-hand stamp is Scott 41? As for the left-hand stamp, the above-mentioned sites don't seem to show a difference between Scott 52 and 60.

BTW, what color is "bister"? Scott used that term.

Granite paper has visible threads throughout. That is Scott 60

Scott 41 should be gray on white wove paper. Your stamps don't look gray on my monitor
But color can vary among monitors.

Regardless they are inexpensive stamps

I'm not asking for the money, but to identify the stamps.
For me, any stamp over 1$ is a catch.

From Merriam-Webster
1: a yellowish-brown to dark brown pigment used in art
2: a grayish to yellowish brown

Philatelically, I think yellow-brown.