I picked up an Aerotech 1706 motor locally and got 3 K185 reloads that were in motors ready to fly for 4 years. i have not taken the grains out of the liner yet but the top and bottom looks fine (no swelling) but has some light oxidation on them. I guess my question is if I scuff these lightly with sand paper will they be ok to fly? What about the O-rings? Below is a picture of an end. I put them in an airtight bag with the air pulled out for storage.