SOLVED. Middle-grade fiction 1970s. Some children go into a large house or mansion and do some damage to it. [s]

[Dora]

The children that go into the large house or mansion that vandalizes it are caught and their parents agree with the old man that owns the home that they should be punished by cleaning it up and also helping him with repairs. Besides learning their lesson they also learned a lot about the older man when he was younger. This may have been a Weekly Reader or Scholastic book, I'm not sure.

[Rainbowheart]

The Vandals of Treason House?

When sixth graders Izzy, David, Marie and Ham are arrested for vandalizing an old mansion in an incident that was mostly the fault of some high schoolers they are afraid to turn in, the four are sentenced to do one hundred hours of cleanup work for the house's owner. The punishment turns out better than expected as they begin to find all sorts of interesting secret rooms and relics, and when the house is about to be demolished for an airport parking lot, the children begin to research its history in a campaign to convince the local historical society that it is worth preserving. The plot from here on in is fairly creaky -- with David making discoveries in a few days that have eluded town historians for centuries, and kindly Judge McGruder's last minute intervention saving the day. But the old house's past, which includes a Tory spy, a religious sect called the Nahumites and a charlatan phrenologist, is curious enough to justify all the fuss.

[Dora]

rainbow art you did it again, this is it. Thank you so much.

[Rainbowheart]

Awesome, glad to help out!