Thank you Kaorte for your response.

I do have an extra piece of flexwatt laying around somewhere, perhaps I can use that with a dimmer switch to get some extra heat onto the cool side.

I found my email invoice for the cage. Its a Reptile Basics 2x3 cage, they appear not to sell them anymore.

He has a history of hunger strikes during the winter, but he started early this year and is going late. This is the longest he has ever gone without a meal.