Older 9x15 Shed- Riding Lawn Mower Weight OK on Floor?

Older but sturdy 9x15 inherited shed. Studs are 24" apart. Floor is approx. half an inch (photo shows additional wood support that =2"). Not sure if this is enough info but wanted any idea if the shed can accommodate storing a 500-800 pound riding lawn mower or zero turn. It already houses other equipment but obviously nothing of this weight.