On mine, I have put colored bulbs under all the white inserts. And some colored bulbs in some places of the GI. Like this, it's more colourful. I will put pictures or video later.
I've added a metal wire to protect the left bulb, near the left star.
On another Black Pyramid, I've seen a nail at the beginning of each lane, to reduce the entrance and make it harder. I'm not for this. Well adjusted, this pinball can be really hard. It's the case of mine.
I don't like the Medusa bumpers because it's not a Medusa, nor the Medusa targets because each target has its own insert colour on the playfield.