Yes, there are more fuses. There is the stock fuse box which controls all the normal car electrical components.
The Porsche (1976) uses a bullet type of fuse, where the filament is external to the ceramic component. I've never seen these before, but a couple were broken, so we starting switching a few, and then the signals worked (WOOHOO!!). Unfortunately, now the headlights didn't work. Luckily, it was because we pulled the fuse for the headlights to swap with the signals, and a quick swap back confirmed it was because of the swap.
The original fuse holders are tarnished, as are the fuses themselves. We've ordered the replacement fuses and are going to change out all of them, since they look original to the car and some of them have questionable status when they are put in. We are also planning on replacing/revamping the fuse box itself, as the contacts are worn and tarnished, and that is hurting the performance.