I'm not who you asked the question of, but I do sometimes make use of archive/deleted/history tables. I'll refer to them as history tables from here on out.
In short, I leave data integrity to the original table and drop it for the history table.
The history table isn't identical to the original table. It has it's own primary keys that are separate from the original table. It doesn't include the original table's unique constraints or foreign key constraints. It also generally has a timestamp to know when the record was put there.
