I requested and received an older book from the 1960's that has no ISBN.  I've read the book, and now want to re-post it.  I'd rather not post it via the Post A Book Without An ISBN Number page--because that just creates another too vague book listing.

However, if I go to my own Transaction Archive and click on this particular transaction, right there it says I can "Post This Book".  I now notice that that listing has an ISBN number that may or may not be accurate--which is how the member I got this book from posted it.  Can I (or should I) re-post this book this way (from my Transaction Archive)---or should I post it via the Book With No ISBN number?

I hope I'm making sense!  Thanks for any help!

listing has an ISBN number that may or may not be accurate - what do you mean by this? Is it using a real ISBN #? If it is a PBS assigned short ISBN (5 or 6 digits) then you can use it since you are sending the book the originally was given that number. Just read through the details and make sure they are correct. If it shows in the system by a real ISBN and the book does not bear that number, then you need to post it via the Book With No ISBN process.

That may be just a warning that the information the book listing (like page numbers, name spellings etc.., )might not be accurate since it was a manually added listing. 

I think you are fine to reuse that ISBN.  Just make sure the information is correct and matches the book you have.

If they posted it with a 'real' (10 or 13 digit) ISBN, the rules say you shouldn't use it. If it has a PBS-generated ISBN, then sure, it's the same book as it was last time it was posted, after all.

Sometimes the older books have a ISBN number on the copyright page.  Or on the spine for paperbacks.

The short five or six digit one is a PBS generated number.  It is fine to repost with that number.