I'm not sure why you wouldn't just contact your agent and talk to him/her. That's what they are there for. It's always a good idea to have any big ticket items listed and insured separately. However, be aware that just having them insured doesn't meant you will get the enough to replace the machine unless you have them insured for replacement value.
Rob's advice is exactly what I was told by an estate appraiser. Have pictures and documentation on anything big items. There is a cap on what your can receive for the contents of your home. It sounds like a lot of money when you are reading the policy, but if you had to start replacing everything in your home that $50,000 isn't going to go that far.