[LS short box]

The company I used to work for we had our own powder coat shop to do our machine frames and out side work. What ever you do don't spray new powder over the current powder. As said above it won't turn out well. Sand blasting will take awhile because the powder is plastic and the sand kind of bounces off the powder.
I know you picked out a color you like but the best powder colors are the ones the they spray everyday.
If a customer came to us with a "custom" color typically referred to a "RAL" number we always did a spray out card and sent it to the customer. Not just sample card from the powder supplier.