Is the really a 6hp?

I’ve been trying to get this motor running with little success, but went into local Yamaha dealer today and checked out new 6hp motor. The new ones are tiny compared to my Mariner, and from my memory of the 6hp Evinrude I had as a kid, the Mariner looks twice that size. The Mariner has a massive prop on it compared to the Yamaha (which is similar in size to how I remember the Evinrude). So just wondering if this is indeed a 6hp Mariner? The 6 on the cowling is suspect, but it’s not in great condition anyway. These are some pics of the engine and the only identifying numbers are on the engine block. The numbers on the plate on the leg have been rubbed off. I know some folks have bigger engines but put “6” stickers on cowlings as 6hp is the max for unlicensed operators where I live. Hoping someone can help shed some light. Many thanks.

They looked the same as a 6 / 8 / 9.9 / 15 HP .-----All the same packaging.-----The 15 HP models may have had bigger displacement.

Ok, I can understand maybe 9.9 but same as 15hp, no wonder the little 6hp looks so big and heavy duty. Got it running now, so will see how it goes in the water