I have no idea what this guitar is but I don't think it is as old as he thinks it is. To me, the basic guitar looks like a catalog guitar from the mid 1920's to the mid 1930's. However, it does have features that don't fit this time frame.
I think it is unusual for guitars from this period to have pickguards. You don't see a lot of pickguards on flat top guitars til the later 1930's. Also, guitars from this period tend to have fancier inlay than this example.
It's clear this guitar has undergone a lot of modifications so who knows what is original and what has been added. I doubt that it was homemade originally, but I don't doubt someone may have whittled on the neck to flatten out that ridge. The unfortunate reality is that it has been neglected for so long it's now basically worthless other than what the tuning pegs might fetch.
Take the strings and the duct tape off and hang it on the wall.