It seems that new people keep asking the same questions over and over. This is a forum for PICTURE FRAMERS, more or less. A few nuts, (you know who you are) but mostly framers. Not conservators. We get help from Rebecca and Hugh, two great resources, but they are going to tell you just what the framers are going to tell you. Call a conservator. Unless you are qualified to do removal, don't do it. If the customer doesn't want to pay for a conservator, then it stays the way it is. Maybe the customer should go back to the original framer and ask for help in paying for the conservator.
Don't mean to sound grouchy and in the "Olden" days, I would have wanted to help the customer also. Time has proven over and over that I am better off being a framer, which is what I am qualified to be.