Understanding Blocked Punts: Scoring & Rules in Football

Question
this happened last friday night.  4th and 6.  punter kicks the ball into the back of one of his own blockers.  they fall on the ball 4 yards behind the los.  since it was 4th down we get the ball; but how is this scored?  the consensus is it's a team block, the length of the punt is 6 yards, and it's a team return for 4 yards.  is this correct?

aside - if they had picked up the ball instead of falling on it could they have advanced it?  i think not as this should be treated the same as downing a punt.

aside - if the ball goes beyond the los i "assume" it's treated as a normal punt.

Answer
Just as a clarifying question.

If "they" is (your team) and the ball is in the backfield then the punt would be a negative 4 yards (because that is where it ended up from the line of scrimmage-and that is how we measure punts- from the line of scrimmage and not where it was kicked)

Although the NFHS rules as I remember them try and conform to the NFL as much as needed on the basic rules of the game- then either team can recover the ball and advance it-so yes either team can advance this punt-and if they would have gone past the 6 yards needed they would have a first down.