I believe that closing the crack is going to be necessary to get a good repair. Can you seperate the two pieces? I would try to get it apart, pull the pin and reclean the split with another soak to be sure all oil is gone. you could reinser a pin and even add other reinforcements and then bury any reinforcements in colored epoxy, clam it up and let it cure. I like to do another step and that is to wash off any overrun of epoxy with isopropyl alcohol. Just wash the exterior wood don't clean out the joint. this will save a lot of work.
bill
