Brian, one of my large pumello tree is a Chandler tree. I have many varieties grafted over it but I still get some Changler fruits from the lower branches. Your fruit looks nice, the Chandler fruit will hang on the tree for about a month after it is ripe so you should not worry about it getting over ripe if you wait. From your photo, to me it does not look ripe, it is still green even if it reached it maximum size. There are two methods I use to determine if I should pick my fruits, the first is you can wait for the skin to turn more yellow overall than it is green like your photo. Also check you fruit now by lifting it upwards, remember how heavy (or light) it is. If it feels like its not 2 lbs for that size fruit, wait until it feels heavy. The last thing is, when the fruit is fully ripe and hanging to long, you can just lift it and slightly turn it, if it falls off the stem it is ripe for eating. Main thing is to let it get ripe, so you get the best flavor.
The Chandlers they sell at the market is always green since they pick it before it gets fully ripe, but at home you can wait until it turns yellow. My pummelos start to get ripe in Dec, and goes until March here.