Tissues and toilet paper work well for cloth seats. I do a very fluid mixture of water and white glue, tinted with the final color of the seats. Cut a piece of tissue oversized for what you want to cover, then lay it in place. Dip a brush in the glue mix and touch it to the tissue. The glue/water/tint will wick it's way through the tissue, then you can us the damp brush to push the 'fabric' into the texture and shape of the seat (done very gentlt and carefully, as wet tissues tend to tear easily). Once it is dry, you can trim away the excess with a sharp #11 blade.
Once it is completly dry, you can paint or weather to your liking.