Another 65? On Cover Question

Hi Guys. I bought this yesterday and am looking for opinions both on colour and on date (maybe a clue in the cancel?). Somebody has written in pencil 1864, and then somebody else, I presume, has tried to erase it.. I have also pictured it beside some other stamps in the series just to give an idea of its' shade. It does not seem to have a grill but I don't really want to take it off its' cover to make sure..
All opinions and comments welcome

Hi. Thanks, I did see that post and I know it is almost impossible on the computer to define shades or colours.. but was hoping somebody might be willing to take a guess, or maybe recognise the orange Boston postmark and be able to put a year on it.. I don't know or have not the experience yet on these matters.

It could have been 1864 or it could have been that somebody thought it was 1864 because of the shade. I see an awful lot of these covers that have a penciled-in date and wonder if that date is accurate because possibly the person who took the document out of the letter penciled in the date. Will continue to be a mystery...

Very pretty shade on this one though and it definitely could be 1864 as its very lake-y looking to me on my phone....
Ray