Here's another mystery piece from my collection. I'm not 100% sure it's genuine LEGO, but I would love to know whether it is, and if so, what part. It attaches to the bottom of a 2x8 brick securely. No markings to identify branding or part numbers, but other legos it came with were from 1970s era.
It kind of looks like it ought to be a curved roof peak, except it's upside down. Maybe the bottom of a boat hull? But what about the notched slots on the bottom?
* there is a small crack in the narrow end of the brick. The left side is what both sides should look like.