Yup, Greping is what Ive been doing for about a month now 
That tensorflow::experimental::tensorhandle class is very interesting, but unfortunately it looks to be something a bit different from the TensorHandles returned in execution. There is a Resolve method in the tensor_handle located in core/common_runtime/eager/tensor_handle but it doesnt unwrap to a Tensor, instead unwraps to an AbstractTensorInterface which is something I havent looked into yet.
An Ideal scenario  for me would be a path from the tf.Variables  for model variables in the model dictionary to the actual c++ Tensors themselves if pointers are followed but probably isnt a thing