Looking at the pits, I suspect that it is BD. Under the fuzzy green, BD will form a hard
type as it progresses, and will be pale, almost a white, green. I would treat this now, you will have some
pitting, but it won't progress. I
had though about using one of the compunds used for re-storing
wood that has been dry rotted. I [in theory] would soak into the green
area and harden it[ one
type is called "
wood petrifier"], also make it water proof so no further moisture could be absorbed. The main draw back is that it would be one way as far as I can tell, but I have not tried it as of yet. I would go for the
standard treatment at this point.
Bruce