Ask, and ye shall receive.....If it wouldn't damage the humidor, I'd say nail it on :squinteye As others have said, that analog is probably worthless anyway.
Since you already said you will get an electronic hygrometer, let me extend the life of this thread by at least one more post: Know what I really want?
A WiFi hygrometer that can sit inside my humidor and lets me check the RH inside the humidor from my smart phone or tablet.
http://www.canadahumidor.com/hygrometers/humidor_alerts_remote_monitoring_kit/