Greg
This, from an article by Peter Manuelian, suggests that the statue was legally allotted to Hildesheim, and that Boston legally got a separate relief – on loan to Hildesheim from 1982, but supposedly now back at the MFA.
"Hemiunu’s massive tomb was unearthed in March 1912, just beyond the Museum Expedition’s allotted portion of the great Western Cemetery at Giza, within the area designated to the German/Austrian expedition. The relief fragment, however, turned up in December 1925 in the debris southeast of the tomb, within the area formally assigned to the Boston expedition. A spectacular, life-size statue of Hemiunu found in the tomb
was sent by the Egyptian authorities to the Pelizaeus-Museum, in Hildesheim, Germany, while the MFA was allowed to acquire the loose relief fragment." (Italics supplied).
Lee