Sorry to hear the challenges.
Soon after buying our preowend Disco, I also needed the code. I was told that a number of dealers will write it on the radiator top or in the front area under the hood.
After hearing this I thought it rather defeats the purpose to make it so availabe, I prayed it would be there.
I opend the hood and in black marker was a 4 didget # that worked. Thank the Lord.
Maybe this will help.
Good luck.
Michael