Question About A Cover's Date 1861, 1881 Or What?

I was browsing ebay for covers when I came across this listing 163087243144

On the back the receiving office has the CDS with the date.

The seller listed 1861 in the title. When I copy the picture and enlarge it, my eye sees 1881 the second 8 having retained a drop of ink.

I want to make this clear I am not bashing the seller for making a mistake just trying to ask more knowledgeable people to help educate me.

-MV

The earliest this could be March 1870, as this is the first date this design was issued.

Good to know I wasn't sure when the design was printed for the first time.

-MV