That damage is from too much slack in the stays? Jeez, it must have been pretty windy that day!.
It's not as bad as it looks.
That repair should be a piece of cake. Everything you need, tools included can be purchased at wallmart. If it was me working it I would first remove the compression post and wrap it in cellophane to protect it then use it for fitting and sizing. Then I would grind out a vee around the split open areas. Then fill to the surface with fiberglass re-enforced bondo (compression post in place). After it hardens grind it flat and rough up the area around it where a cloth patch will go. Then using fiberglass cloth in several layers, each one slightly larger that the next, cover the area. Using a small paint roller pre-mix the resin and wet out the area(s) as the layers are added. If you should encroach on the compression post hole just wait for the resin to harden and cut and grind the excess away. Then maybe with time available I would use some more of the bodo to smooth the repaired area and sand it all flat to blend it. Then I would paint it and it wouldn't look all that bad.
Tools, disc/dual action sander and course, medium and fine grit discs. A drill with 1" drum sander. Bondo spreaders.
Supplies, A quart of Fiberglass re-enforced bondo filler. A quart of fiberglass resin. Two packages on fiberglass cloth. Paint. Masks, gloves and eye protection.
A DS 1 does seem tougher that the DS 2, at least the one I used to have. The top deck was much thicker and stronger than my DS 2.
I know that you have sentimental attachments to yours but that Hunter green hull with the yellow stripe and the ivory deck looks pretty darn nice.
Good luck,
Carl