Right now it is not possible to verify or even view all the custom object data that is tied to a lead in the UI. We use the custom object as a many to one relationship to track all the "objects" a lead owns. Right now it is not possible to see what objects a lead has. It would be a great feature if at the top of the lead just after the "Order Info" tab there is a new tab "custom object name" that shows the custom object data for this lead. Should be easy to build.
.png)