Welcome to Bladeforums db86
There are two ways to post photots-
1. You need to sign up at a free photo hosting site like Imgur, create an account, then insert the BBCode that the hosting site assigns to any individual picture in your post here on the forum.
2. Purchase a forum membership that allows you to post pictures directly from your computer. It's one of the benefits of a paid membership. To learn more about paid memberships click on "Paid Subscriptions" in the blue banner across the top of the screen.
As far as your situation with the knives, I don't know how you could go about getting COA's, but if the knives are custom made, and if the makers are still alive, you might be able to contact them and get a letter from them authenticating the knives and what they were made for (like a Clint Eastwood movie).