I am fairly new to food connoisseurship, so I have a couple of what may appear to some to be stupid questions. Basically, I am making Macaroni Cheese and Garlic Bread for dinner, and I have some spare dried Coriander leaves. By what method and process is Coriander best added to Macaroni Cheese? Should the Coriander be added during cooking, or after cooking? 
On this site, when it comes to questions about food safety we defer to official guidance (overcautious though it may be). In this situation, you won’t find much official guidance, simply because the idea is absurd. Lead has been banned in cookware for (IIRC) more than a century. While creating an epoxy barrier might be sufficient, it would be difficult to ensure that this was done correctly, or that the barrier did not crack or otherwise fail over time. It's a nice looking grinder. Use your epoxy to glue it shut so it can never be accidentally used (remove and discard the grinding surfaces, just to be certain), and put it on a display shelf. That, at least, should be safe. 