Tips on buying a used 1991 Mazda Miata NA

I'm buying this used '91 mx5 NA within the next 3 days, but looking at today. Is there anything i should out for specifically / dead giveaways that i should just walk away from it? Thanks. Here's the craigslist ad.http://ift.tt/2sRtQcq via /r/cars http://ift.tt/2tmiC3l