I contacted Ellon Library, who respond as follows:

Hi,

None of us have heard of the sculpture. He did one at Collieston near
here in 2000 but it was called Sandstone Sea Hole. The only place
called Logie really close to here is Logie Buchan, but there is no
sculpture there. It may be located at Logie Durno about 15 miles from
here. I am waiting for word from Aberdeenshire Art co-ordinator and
Aberdeen Art Gallery. There are a lot of Penpont Cairn illustrations on
the internet which is frustrating. Will let you know if we are able to
locate it.

JennyHyland
Senior Assistant