Defered maintenance causes the most problems. Catching up after deferred maintenance takes a while (and usually costs more than if it were done properly in the beginning...).
I'd suggest changing all fluids including a cooling system flush, check of valve clearances, check the brakes (and if of unknown vintage have the brake flexible hoses replaced and the brake fluid flushed). Inspect carefully for rust - the inner sills/floors and rocker panels make up the main strength of the Spider's uni-body. Rust in the spare tire well is usually not structurally a problem (but you don't want your spare tire falling out either...). Clean all electrical connections - battery terminals, ground cables, etc.
Don't neglect to post some photos. We likes photos. They could even be of your Spider.