DIY Making a wood handle for a wood speargun

On this gun I had to do something a little different to fit the handle. I couldn't use the original thickness of the board for the tenon because the stock was too thin to hold it. So I reduced it by about %30. I got the stock dimensions down pat now for the next gun (if) so I won't even have to run it through the planer when I get it from your dad. I don't really need another gun but I keep wanting to make one that's mistake free along the way, it's a silly pursuit.

Pics of the handle for the new gun.