It's a helpful place to start, but my friend (who badgered me to create an inventory) put his "current inventory" somewhere that it hasn't been located yet.
Several weeks into the process we located some of his "old" inventory and notes - but no "current" documentation has been located yet.
Make sure that your family can find your notes and inventory, put a date on any documents that you create, put the cost you paid and the approximate date of purchase.
Notes regarding why you paid $7,000 for what appears to be a $250 rifle are important, along with a list of any accessories which belong together.