How To Merge Repeated Keywords in iPhoto?

Hello all. I am curious if others have seen this behavior in iPhoto.

Looking at my Keywords list I was surprised to see many triplicated. I would think iPhoto would not create or accept Keywords as NEW if the words already exist in the list. I have rebuilt my library etc.

Curious if others see this problem too. (And I just updated this with an additional weird/buggy behavior aspect). Love to see if someone can test the two aspects described below!

I did not just want to delete any two out of three as I cannot tell at present if that would leave some photos without keywords. e.g. if I have 100 aircraft photos and Aircraft appears three times as a keyword maybe all 100 photos have one WORD "Aircraft" in their keywords, or maybe 30 photos have Aircraft (first instance of keyword), 50 have Aircraft (second instance of keyword), etc. and deleting the second instance of the keyword would leave 50 photos without a keyword.

I may work around it by first searching for ALL photos with the Aircraft keyword, then add some test or temp new keyword (e.g. Aircraft123) to track these photos, then delete all three instance of Aircraft from keywords, then create an add a completely new keyword Aircraft to the photos, and the delete the temporary Aircraft123 keyword.

{Yes, I could just rename Aircraft123 to Aircraft at that time, but I am describing doing it to make it completely clean}.

But clearly this would be painful to go through doing to hundreds of keywords that are duplicated so I figured I would ask all you smart power users for input.

Regards

Imran

PS I found something interesting and even more buggy in searching for Keywords. "Even Stranger, iPhoto Does Select ALL Three Instances Of Yachting Keyword Even When One Is Clicked. But it also says NO Photos have this (these?) keyword(s) WHILE it actually shows 117 photos!" See this screenshot.