2.2 mazda perkins. should I buy
 

I have the opportunity to buy a 2.2 mazda perkins with the 4 speed for $600. Seller says it runs with only 84k miles. Ya sure.

It has been sitting outdoors under a tarp for who knows how long. I know they are somewhat rare but also very expensive to fix and get parts for.

would anybody else make this gamble? Any thoughts or advice would be appreciated.