I recently picked up a Dual 1210 with a Noresco base. There is no bottom plate on the turntable. I compare it to my Dual 1225 with a Dual base which has a bottom cover stapled to the base. There are eBay ads with similar turntables that also look not to have a bottom plate. I would think that without a cover the turntable would suffer from vibration and dust. Am I missing the plate or is this normal?