Our Scag is a 2017 model that we purchased new just prior to the 2018 mowing season. It has a 48" deck and "ZK" transaxles. I hope that helps. If your mower has the engine rear guard, with two square holes for carriage bolt heads, I purchased this rear hitch (see photo) on-line from a third party but painted in the Scag color. I have not towed anything behind yet. I just use it as a tie-down point when trailering.
Thanks War Eagle! The bolt spacing is the same (3") on the engine guard. Knowing the 36" uses the same ZT2800-ZK I'm gonna order the hitch and try it out.