Someone gave me a box the other day to test out an old Crown Graphic. It's EM. # 27 18 10 EXP. 06/92 I was thinking to go with E.I. 10 or 12, but haven't had much experience with '52, as I usually use '53 and '54. So I am using my knowledge of 400 film ('63, '53 and old 400 color) to guestimate a working E.I. Should I rate it faster, as it is slower, or would seventeen years of room storage do about as much fog damage to 100 film as seventeen years of refrigerated damage would do to 400 film? Is this source of 4x5" film a good one, or should I just buy new stuff elsewhere?