Dolly,
That burn has destroyed what ever collector value the cabinet had. It won't hurt it any more to carefully the top, I'm sure the glue under the veneer has died due to the heat. Then sand just the top, stain it to match, shellac it, wax it and make it better again.
That is what I did with my Singer 9W-7 treadle. Here's the thread I did on it:
{
http://www.quiltingboard.com/vintage...e-t204377.html }
I've also got a Franklin 1911 in a Parlor cabinet I had to repair the bottom of. I paid no mind to the question of value as that was gone due to the water damage.
Joe