In answer to your questions:
"what are those toggle levers underneath the boom near the tack?"
~ 3 cam levers on the underside of the boom at gooseneck are rope jammers to hold the two leech reefing lines (and outhaul) when under load.
"has anyone set up double reef lines and led them back...
A beast of a job
This is a beast of a job!!!! If your E26 is tiller-steered you may have more elbow room? We have an E26 1987 with wheel steering, thus quadrant, cables and pulleys are all in the space photographed by SurabyaKid. I was able to replace both thru hulls (with bronze fittings) and...