I took ideas from the various stepping systems and came up with my own rig for stepping the mast on the trailer. It centers around a folding extension I added to the trailer's mast support.
Here is my trailer's mast support. I nested a lightweight galvanized steel fence pole in the support channel. It pivots on the bolt that is about 8" down from the mast cradle.
Here is the extension erected. Not visible is a small clevis pin I insert to keep the pole vertical when there is no load on it. After buckling my first pole, I added a stay that connects to the tongue to brace the pole.
A pulley and the stay attach to the top of pole.
I use a carabiner clip to temporarily attach the stay to the trailer chain.
I use rubber bungees attached at the frame corners and to trap wires to support the mast laterally while I am raising it.
Edit: The bungees deteriorated quickly, I even had one break so replaced them with fixed lengths of cable with hooks on each end- I attach end to a trap thimble and the other end over the cross bar and hooks onto the end of the dolphin striker. Determine the length with the mast up.
While the height of the pole provides enough angle for the winch rope/jib halyard to lift the mast, as a safety measure I usually temporarily support the mast with a small piece of board to increase the angle slightly.
Here the mast is almost all the way up. You can see that I attach the winch rope to the Aussie jib halyard. I sometimes need to help the mast base into the step with a slight push. It looks like the extension pole is bending, but that is caused by my wide angle camera lens.
With this simple, inexpensive, rig I can easily and safely raise and lower the mast singlehandedly. Everything stows neatly out of the way when trailering the boat.