I am considering installing a new starboard bulkhead to attach to the existing chainplates. The existing bulkhead has some rot & water damage. The boat is in the water-- can I do this project with the mast up?? I have two (2) spare halyards- mainsail and spinnaker-- will these hold the mast up during the repair process when there will be no chainplate support?? Also- has anyone tackled this type of project (new bulkhead) with the Oday 272?? thanks