Toilet In-Use Lighted Indicator

We only have one toilet stall for men and one for women at work. One of my work mates suggested an airline style lighted indicator for when the toilet is in use. This is my solution. The man and woman icons come from this thing:
https://www.thingiverse.com/thing:1807800

I'm using a 12VDC wall plug pack with automotive style LEDs, and a small micro push button that the door presses when closed.

The tab on one side of the lid is too long and covers the screw holes, but rather than redesi