Personal Stash Old No. 7 - Quality Control?

I've had stashed a couple cases of JD Old No. 7 for 30 years. Most of the 200ml bottles look pretty good (great seal and full). But a few have sort of evaporated even though they are sealed. I'm wondering if anyone has ever experienced this? I'm thinking about contacting Customer Service at the JD Distillery for their input (may even ask for replacements). What's the group think? Call this a "Rocky Mountain High Experience & Disappointment" or the "Case of the Faulty Seals & Evaporated Sour Mash".