tell you what i did. went to wally world and got a camping toilet . not much more than a five gallon bucket with a lid, seat and liner. it fits perfectly in that small area and with dry chemicals doesn't smell.
with time, the oilcan effect should work its way back out. saw it done on an Erickson 25.
attach a pic of the crack to your reply post. paperclip is on the posting toolbar. although it's hard to see. youll have to reduce the size of the pic or it takes forever to upload.........
Self Proclaimed Genius