Try connecting the mast at the base (tabernackel) so it wont jump about then walk forward with it (It obviously gets lighter as you walk forward) then take up weight of it through kite halyard attached to bow. Once you can get to the bow just then attach forestay.
Altenatively create an A Frame from two kite poles or similar, these are attached at the shrouds each side, then run a block n tackle system using the kite or jib halyard and take up slack until this system takes the weight. You can run this through a winch to make it easy too. (I used this system on the M27 but needed 2 people as mast is much heavier/longer, a spacey 18 should be pretty easy this way)
(Much easier job with two people and very much easier if mast base attached to the mast step in a hinge/tabernackel arrangement.)

Thanks for the info. I wonder if I have an extra heavy mast as just lifting it up from the stern rail is a big effort. I was just looking at a video of a guy raising the mast by hand on about a 25' boat. He leans a long pvc tube against his cabin door and heaves the mast onto that. Then he climbs on the cabin and yanks it all the way in place as if it was made of balsa wood. If I tried that, the mast would be supported at less than one quarter of it's length by the pvc tube and possibly bending and breaking the mast at this point.

Just saw a fantastic method if you google Mast Raising on Fabola Campus 650