Mystery Machine Buried in Marsh ID'd: Vintage 8' Spike Harrow - Misplaced Decades Ago - Recovering

Only the control levers and adjustment plates visible above ground. Thanks to CWL for tagging it as a HARROW. Ok, good. Look those up and focused on the smaller walk-behinds. Or random DIY frame? Nope on both counts per usual. Commercially-built 8ft spike harrow, identical to pictures thus far. Not only did it turn out to be 4-5x as big, heavy and irony as expected. But the digging's started; got half of it levered up on braces.
The last few pictures show excavation progress as of today.