How Do You Find Local Carriers Post Office? Prexies On Cover Question

I have a bunch of single franking prexie 806 on cover with local address and post office.
How do you find historical carriers local post office?
Is there a book or site for this type of historical research?
RT

You look it up in the corresponding July issue of the USPOD Postal Guide. <<<<That teaches you to fish.

Unless on John Becker does it sooner, I will look it up in 3-4 hours.

Edit:

Give me one or two examples, date, city and state and I will show you. Pictures would keep it interesting.

Thanks for the help. I am always learning here! It's GREAT!

Here's one

Always best to work from an illustration. Many thanks for adding one.

In this case, there is a street address and Roakone would clearly be large enough for city delivery, and is a "1st class" office. The 1954 date and 2 cent rate would point to this being a single-piece third class rate (effective Jan 1, 1949), in this case an unsealed Christmas card, which the envelope dimensions also point to. It may be sealed now, but no doubt unsealed when it passed through the mails. Also, it should have been cancelled without a date, but that was often overlooked, likely in the interest of speed during a time of high mail volume.

Local non-carrier items would typically look like a general delivery letter and be missing a street address and be sealed like this cover:


As for lists, the Postal Guides varied over the years in the way they indicated carrier offices. In this case, Roanoke had carrier service, so this can only be 3rd class.