To expand on Hobbiano's comment above: FWIW, OP, both non-aero hoods and 27" tires also appear to be available on Amazon and eBay. Just make sure whatever tires you buy are the correct BSD (should be a BSD of 630 for a Miata, or the older standard 27" x 1 1/4" size and not the new so-called 27.5" type..

Also FWIW: in the photo, the brake hoods on the bike look to be in quite good shape (like the rest of the bike). If they are - and you end up getting it - maybe get a spare set of hoods for future use and use those on the bike now until they need replacement. Cane Creek non-areo hoods aren't terribly costly; neither are Dia Compe hoods. Some other "knock offs" are even cheaper. And having a spare set should set you up for the foreseeable future in case they go out of production.

Regarding replacing the existing brake levers with aero levers: aero levers (and aero cable routing) has advantages, but also complicates matters and isn't without disadvantages. My take in this case would be: "If it ain't broke, don't fix it."