The reefing system diagram for the H35 Isomast boom looks like the diagram below. However, the actual installed system may be slightly different, or at least, how I rigged ours up is different. The diagram is a "generic" one so the boom vang mast attachment with the stand-up block isn't there so one has to rig up a block, or couple of blocks, at the base of the mast. The other thing that may be different is the lack of a sheaves at the gooseneck. I don't recall what was or wasn't there but this is what the diagram has.
Also, for the outhaul, there is a cable and a block inside the boom with the block being somewhere around the middle of the boom and the cable terminal somewhere near the gooseneck. Take a flashlight and look inside the boom from the aft end and see if there is anything there.
The reefing block in the middle of the boom is called a "bullet block" in one place and on this page it's called a "shuttle block", but bullet block seems to be more common from what I've read. The lines on the leach that are shown coming down and then just end, on the previous page are shown being attached to a boom pad eye. I just attached mine to the boom end above the sheaves.
I used to have a reefing system set up like this but since I take the sails off at the end of the season I've just reverted to a single reef system.