Thank you for the links. I decided to look a little deeper into the role of quenching on defects, and found more supporting evidence:
http://www2.umist.ac.uk/material/res...u/al4cu01t.htm
"Rapid quenching also preserves the large number density of vacancies in the aluminium lattice from the high solution temperature." -edit: Not really relevant since the alloy is Al2Cu.
So it appears I will be lapping the block just enough to remove any impurities (oil, dirt), then annealing (is it correct to use the highest temp in the annealing range?), then fine lapping.