I was looking around at the debris. I'm pretty confident that we could lift the majority of the ledge back, especially since the force of the blast broke it into smaller pieces. The presence of two bolt anchors above the ledge, and large tree anchors on the ground, is advantageous.
I have 100m of static line and about 50 meters of 1'' tubular webbing left over from a previous spelunking hobby. I'd be willing to donate it to the cause.
We'd probably need another 100m of static, and a couple guys on the ground to haul.
What sort of epoxy would be best? There would be pieces missing, but I'm pretty confident we could glue most of the big pieces back onto the ledge. It *is* flat, after all.