I am an insurance agent, not a claims adjuster, so don't take my word as gospel here. Replacement Cost is typically the best way to insure something, because depreciation is not involved in the claims settlement. With rapidly-evolving tech items (like A/V Receivers), this can get a little tricky.
From a replacement standpoint, it's impossible to replace a 10-year-old receiver with a new receiver with exactly the same features, because they don't make them any more.
More than likely, you would be looking at replacing it with today's equivalent in terms of features, pricing and quality. So, for example, if your Kenwood receiver was a mid-line receiver in the Kenwood lineup, and competed with other mid-line receivers from other similar manufacturers, they would likely offer to replace it with one of today's mid-line receivers.
The insurance company would not be obligated to replace it with a receiver with S-Video connections, for example. If that is something you absolutely must have, they will most likely offer you a $$ amount based a mid-line receiver, and let you go out and find one that has S-Video inputs, and let you pay the difference.
For most people, this ends up being a good deal, because they replace old, outdated technology with the latest and greatest. Unfortunately, it looks like that's not really what you're wanting to do.