"As it were, ..." is past subjunctive mood. The ordinary past tense is "As it was,..." Both are correct, but in different contexts. The ordinary past tense is straightforward. It is used to make normal statements. For example: "We inspected the house as it was last June and found it to be in good condition." The word "was" is used because you are stating a simple true fact. The house really WAS as you saw IT. "Were" is something entirely different. When you say "it were", it is no longer necessarily true that "it was". It might not have been. It might be completely hypothetical or imagined. "It were" does not assert that "it" really "was". In most cases, you do not say "it were". Instead you most commonly say "if it were" and you follow by a conditional statement: "In May, we inspected the house as (if) it were June and found it to be in good condition." "Were" in that sentence makes sense because it was NOT June. It was May when the house was inspected but it was inspected AS IF it were June. The phrase "as it were" is also thrown causually into conversation as a filler - words that don't really mean anything but create an pretense of sophistication since only educated people use the word "were" for subjunctive mood. Few people in the U.S. know how to properly use subjunctive mood, so using it makes you sound smart.