Based on the option sheet for my previous boat, an 82 L25 (I believe the rig is identical or close to the L28), there was an option for a heavier duty rig with two lowers instead of one. Go to
www.lancerowners.com, which Phil has up, but not listed under "brand specific forums" for some reason. Look under the 28 for the knowledgebase and you will find the manual (which is almost laughable). There also used to be a .pdf showing the reefing system, either under the 25 or the 28, that was very helpful. Perhaps BrianD has a copy, as I believe he was moderating that site for a while. I may have a copy at work still and will look for you. Rigrite.com sells Kenyon parts if you need them. I am assuming you have a Kenyon spar, as I did.
The boom likely has three sheaves in the end. One is the outhaul (the middle) and the other two are for the first and second reefs. The outhaul on my old boat secured on a cleat on the bottom of the boom about a third of the way back from the mast.
The reefing lines probably (according to my old boat) are supposed to run up diagonally and through the reefing cringle (grommet) then down perpendicular to the mast where they pass through a stainless loop mounted on the mast. Termination is by simply tying a stopper knot in the line. Warning...don't accidentally pull one of the lines inside the boom...you will regret it.