I think this has been done a number of times...but I haven't found too much on the details of how to do it. I have a dead AM radio in my 69, and I don't want to cut the dash. So I'll leave the dead radio in there as a placeholder. I also don't have the actual glovebox (I have the glovebox door only...no actual box behind it). I was thinking that I'll just run a replacement stereo in there. I found a cheap pioneer radio for $60 on sale (I'm not much of an audiophile). I'm going to run this to a couple of 6x9's in the rear and I'll replace the single center speaker with the dual speaker thing that's commonly available.
I'll post a sketch that shows roughly what I'm thinking of building. It won't work as it's sketched here...the spot for the radio would have to be recessed. As it is now it would hit the glovebox door when it's closed. I like the idea of keeping a small storage space for some papers, like registration and insurance papers.
I'm not sure how this will mount in the glovebox opening yet. That's kind of one of the things I 'm looking for suggestions/past experiences of.
I'm not all that great at these custom fab deals...but this seems easy enough to try. If there are any suggestions, please let me know.