I have each of the 3 speed RC engines and must say it seemed like when I was trying to get them Spencer and Gordon were the hardest to find. Also something to note, at least for the two I have had of the Gordon variety. The controller is very difficult to move. I ended up taking it apart and shaving a bit off the plastic bit inside. It is very smooth now, but there is a hole in the sticker. 
Great find though.
Great find though.
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