I have purchased a 100+ year old log cabin on the river which the DNR regulates any changes done and doesn’t want to permit magor repair like log replacement,they want to see it gone.It however has some small dry rot places and large cracks on the exterior logs what can I do to insure it does not get any worse.it needs rechinking and is painted a dark brown which I would like to lighten back to a more natural color what products and preceedures would you sugest I try.The interirior is in great