Okay, let me summarize what we've discussed and see if anyone has improvements or suggestions.
To step the mast single-handed:
1) Attach mast base to mast step with hinge
2) (with trap wires) Connect trap wires to front pylon by whatever method you feel is most suitable. Should go around front crossbar rather than around side bar.
2) (without trap wires) Run "preventer rope" from front pylon around front crossbar to mast tang then down to other front pylon.
3) Ensure trap wires or "preventer rope" is(are) snug
4) Attach "raising rope" to jib halyard shackle. Ensure shackle is raised to tang.
5) Run "raising rope" around suitable part of mast support on trailer and back through jib sheet cam cleat to back of boat
6) Raise top of mast as far as possible while standing at back of boat, pull "raising rope" tight through jib sheet cam cleat so mast is hanging partially stepped
7) Move to front of boat and pull mast the rest of the way up using (your muscles and/or trailer winch)
8.) Attach forestay
To de-step mast reverse process.
Does that sound good to everyone? I look forward to trying this myself, once I have my new mast base installed.
(My current mast base pictured below is unsuitable for this process.)