请教8老师，给父母 renew 绿卡，填 I-90 的问题

请教  Part 3. Processing Information

1. Location where you applied for an immigrant visa or adjustment of status:

2. Location where your immigrant visa was issued or USCIS office where you were granted adjustment of status:

父母的绿卡是10年前批准的。已经不记得当年的材料寄到哪个 USCIS office 了。另外那个通知绿卡通过的 797(?)表也早就找不到了。根本没想到这么多年以后居然还要填这个信息。请问怎么才能找到相关信息，填上去呢？

感激不尽！