Cabinet is looking great. Was the original cloth to far gone to re-use? There are some nice reproduction guitar amp patterns that would look pretty sharp with the dark mahogany finish. I'm thinking pattern FA 1045, FA 1050,
or DF6002 would go very well with your sets gold trim. I'm afraid black could end up looking like a big dark hole. Of course it's all a matter of personal taste.
http://www.vibroworld.com/parts/tech10.html