Old class c rotted back outside corner

Hi i just bought an older class c its a 1979 dodge triple e (micmac III)
this is only to get me thru the year tell i can get another one. Everything works and is a great unit, except i noticed today that the back left corner has seperated looks like the corner wood has rotted out and the screws let loose. Was wonder any quick fix i can do with that to keep it from getting worse tell i can get a new trailer in 12 to 14 months?

Thanks new to rving and dont know if my idea of putting metal tape down the edge to hold er is the best idea.