While far from the quality of the first party shell, the aftermarket NES shell actually went through a revision and is much improved over the first one - you can differentiate the two if attempting to buy one by the rubber pads that cover the screws, the old version uses shiny silver while the new one uses matte grey. The new one fits better and is got better feeling plastics.
I feel like I missed out on the SP hype train. I was an og advance kid. You got me wanting to pick one up and mod it!