What are you trying to do is actually very easy. You need to locate the item's id in the files more specifically will be on data/stats/items. Once you locate them there will be a line on the item itself that is preventing them from being equipped by non hero characters.
Now i am not 100% since i have never run such an old chronicle server.
As for the "Unique Npc" again is easy. Find an NPC merchant dialog (any doesn't matter which) in the HTML folder and just rename the file with the same ID of your custom made NPC. Then in this file when you open it on the line that configures the "button buy" you will see a "multisell number" you need to find that file, copy it and paste it within the same folder with a unique name (similar to the one that was before, for example if the file's name was 000501 the new unique name must be 000502) take that new name and replace it in the HTML file.
And you are done! Now when you will talk to that npc it will bring up the multisell that you just created. After that is up to you to fill up that multisell with anything you like.
And for any future reference if you want to create something new custom just copy the way from something else OR even better use the "Recycle System" which basically you take something and you repurpose it.
