Since I am a Fender guy….I did find this commentary by a guitarist who was more familiar with your question and perhaps can offer some insight to your question.

It does help a bit, because it does not mention the custom as one of the chambered models, and the one im looking at is a reissue of the silverburst so it may not be chambered. I appreciate your help, however I am still holding out till I see something that directly says they are not chambered which I have yet to find. Again though I do thank you for the effort and it does contribute to my belief that the one im looking at is in fact what I want so your article did still help me :)

I don’t have the time but you should be able to find your answer here or post the question there. Good luck