A. Notary republic doesn't know if your logbook is correct.....you are certifying that it is true and correct.....but really how does any CAA office or FAA know if it's correct....unless they personally flew with you.
A stamp from your employer is good as they can verify employment etc.... But in my case they said they had flight time records only for last 3 years and I had been there almost 14, so wouldn't verify hours but only my position and employment.
The FAA will send your employer or the CAA the required records and training files etc from all previous airlines you have worked for...that is hard to fudge as you don't have access to those.
The whole idea of a stamp is really meaningless and easily faked...that's why I recommend bringing a few other documents to substantiate your logbook.