Sure it's possible, and not all that unusual. Doing some googling will give you many options and I'm sure that the pro-rebuilders will have some suggestions.
It doesn't sound like you need a full music desk, just a replacement "splat," in furniture terms. Suppliers have stock options or you could have a custom designed fretwork piece built to your liking. It could be easily crafted to fit the dimensions, and even hinge locations, to install in your existing music desk.
Here is a company which specializes in this type of replacement and may give you a start on how you want to proceed.http://perrypiano.com/Parts_and_Manufacturing.html
Good luck and have fun with your artistic quest.