Regarding Israeli Tabs

Hello, I was cataloguing some Israeli stamps and came across this same subject here:
https://goscf.com/t/7867
In the replies to that topic, Londonbus1 stated that "The numbers at the top are the date the sheet was printed". I have posted a photo of two stamps from the World "420" Class Sailing Championships issued on July 8, 1970. Based on what was posted by Londonbuus1, these stamps would have been printed on March 15, 1929 (DDMMYY) and June 14, 1976 (MMDDYY), neither of which seems reasonable. Is there another explanation for the numbers appearing in the selvedge edge on Israeli stamps and/or, why two different date formats for stamps of the same issue?

I think that these may be control numbers on the side which can vary from sheet to sheet. Then, there are tabs on the bottom with information about the stamps which are what most collect with these stamps. Also, there are plate numbers on the side as well which are separate from tabs and control numbers. Older stamps have a double tab which is a large tab and a small sheet margin selvage together under the tab. The tab with the selvage is much more valuable intact together than if the selvage has been removed from the tab. Also, stiff and unbent (at the perforations) tabs are much preferred over weak and bent (at the perforations) tabs.

I think jogil hit the nail on the head. Each sheet would have a control number stamped in the selvage.

Thank you for the replies. So, are stamps with the control number on selvedge any more or less valuable than ones without? I have several stamps with the postal emblem tab but missing informational tab; are they of interest to collectors or the same as stamps without any extra edging? I ask because I am thinking or removing the extraneous bits so the stamps fit in my album properly.

There will always be a collector of each type of collectible. That being said, I believe that there is a difference between selvage and Tabs. The tabs most commonly associated with Israeli stamps also have something related to the stamp itself other than just a number. At least on the modern ones. Of my Israel stamps, the tab is below or above and selvage is on the side. I can be wrong, I have a fair collection Of Israel, but certainly not complete.
My preference is to remove selvage when it suits mounting a stamp properly. I do however leave plate numbers intact.