I've recently added a couple of new badge designs to my store - 2001SE and Shinsen NB fender badges.
As you can see, the badges are not oval as the original. They're 50mm like my other fender badges. However, they're accurate in terms of design and color, so they should look quite nice on an otherwise bare Special Edition fender.
revlimiter Badges are available here.
If you've got another special edition Miata and would like to get a badge designed for it, just use a custom order form to get in contact with me and explain the badge specifics. I should be able to make one up no problem.