Thank you both for the reply, these are good tips. I did find the 1871 Rochester directory on Google for Mr Edward Corning, but the earliest it can be is 1878 as 51studebaker mentions September 1877 is the logo copyright. I will also try ancestry.com.
Kimo, great thoughts but I do not think it can be later than 1883 as that is when the 2c per half ounce and 4c per ounce rates went into effect (note above Scott 210 in the scott catalog). I also have such a cover with the Quaker man as a 2c usage, and by 1888 Ravenna cancels were dated.
Another approach might be researching the cancellations. I set a search up for Ravenna on
ebay. I came across this UX3 card with dateless Ravenna, and the reverse is dated in the writers hand as November 21, 1874. It is similar but has a star killer. With enough dateable cancel references it might be possible to bracket as well.
Here is the image used with permission of adman881 the owner.
