If, by a slim chance someone out there is building a Senior20 organ, I have some info. I have had problems with the rewind mechanism in the plans. It calls for a very herky belt this is used on a vacuum cleaner. I have always wondered why that was used. I decided to try some rubber bands to see if they were strong enough. They work great except, they are flat and my "pulleys" are concave where the rubber bands ride so they have a tendency to roll off. I am looking for an "O" ring of appropriate size in length but smaller in diameter, more flexible than the vacuum belt to use. I'm just writing this for anyone doing the build to think about when it is time to worry that rewind mechanism. I have never liked that big ugly belt.