I figure you could use a very simple lazy jack system. My HC 37 with full battened main has only 2 "vertical" lines.
Previously the main sail used to cascade all over the place and with the admiral at the wheel and me alone bringing it down it was a PITA. Usually we bring the sail down just before heading in to the dock. I deploy the lazy jacks just before lowering the main and it keeps everything contained until we are docked and/or anchored and then I go back and secure the main on the boom.
All I have is a sheave on each side of the mast above the cross trees. A line runs up over that sheave (on each side of the mast) and then down to a ring. That ring has a line that runs from about 3/4 of the way back on the boom, over it and then back down to the boom again, about 1/4 of the way back on the boom. It could do with another "vertical" but I got 90% of the benefit with what I have so I will most likely never add to it.
So, you need two sheaves, two rings, four pad eyes, two cleats some line and some overlooked items.
The most difficult part is getting up the mast to mount the sheaves.