have a look at the manual again, i'm not too sure the 5.2 was offered with the delux 4 way jib blocks...the reference to them in the manual may be the 5.5???
from the pics it looks like you have the normal 5.2 setup circa 1979
take the jib blocks off that white line that is coming up the tramp grommet. that is for the helm trapeze bungee, as you state
put the blocks onto the eye of the wire cable in the middle of the tramp. in the pic your jib blocks are lying the wrong way to see the becket but it should be visible on the other side
