How ironic.....
Just about the same thing happened to me when I attended the first DVSF. While in parade, my engine went dead. To make a long story short.... all the glass fuses looked good, but I pulled out the ignition fuse anyway and it came out in two pieces..... the fuse element had broken from one of the end caps, probably due to under hood temps and melted the 'glue' that held it in place. I 'borrowed' a fuse from the windshield wiper circuit and was back on the road..... that fuse is taped to the side of my tool box, first time I ever witnessed a failure like that.... and now you have one too!!
Glad you found your problem without pulling out all your hair
Happy motoring