Bumping this wonderful thread again 
2 days ago I've bought and older (late 70s-80s) racing FD hull with alu mast in mint condition (not sure who made the hull, couldnt find any builders plate or anything, just a laminated sticker of IFDCO builders permit with number, though don't know if that could help at indentifying the boat at all, and came with mainsail numbered DDR-124 -yay gogo east germany- though have no idea if its original sail). I've sailed wooden FD before, though with veeeery simple rigging compared to the new boat (mast couldn't be raked at all, no provisions for spinnaker whatsoever, sailed mainly in light winds for leisure).
After a lot of reading here and there (mainly here in this thread here, kudos to you gentlemen), I was able to indentify most of the rigging on the new boat, though i have question if there's something missing in the rigging of my boat. Yesterday in the evening I tried to raise the mast, though I've encountered a problem. I know the shrouds go under the deck, connected to magic box, for fine length adjustment when raking.
Nevertheless, the ultimate question is about the forestay. I know it should go under the deck fore of the genoa fitting point, however I'm not sure where to fit the end of the forestay - I assume there must some kind of adjustable magic under the deck, because of the varying forestay length when raking the mast. Nevertheless, there are the genoa furling control lines only, and two shock cords under the front deck not connected to anything (reason of their existence is still mystery to me).
So finally THE question - is it possible that the forestay is connected to the one or both the shock cords? Since most of the mast load is taken by the genoa halyard, when the genoa is up, and i guess the shock cord can support the mast when the genoa is not fitted (like on trailer, or when raising the mast), and the shock cord keeps the forestay tight even when raking, eliminating the need for some complex adjustment system. Unfortunately, there is no similar boat in reasonable distance I could compare the rigging to, and the owner just inherited the boat with no knowledge of rigging on it at all.
Sorry for not so good English (I'm from Czech Republic), and I'll post some photos when the weather gets better 
Thank you very much for your replies