Got some samples in today for the production keypad buttons. We went with dome contacts. These will be positioned over gold plated fingers on the main PCB, and they are held in position with a clear plastic overlay.
Also sent out a little mold for the keypad. This is not the production mold, just a quick/cheap one to confirm the keypad geometry works. Should arrive later this week and we can make a few samples by squirting silicone into the mold using a syringe.