I needed to find components which would fit within the footprint of the shield. I knew I could fit the original sized switches on the board, so I needed very small switches. The toggle switches could be replaced with DIP switch arrays; although, they may be difficult to use. The momentary switches were more difficult to replace since they have an embedded spring to return them to the home position. Fortunately I found some limit switches just the right size. I considered using an LED array to make assembly easier, but couldn't find one that was the right size. So I settled on surface mounted individual LEDs. I also decided to put a microSD card reader on the top to support the disk drive. And then as recommended, I added a connector for a SparkFun Bluetooth Mate Silver for wireless serial communication.