Most home policies set a limit on collectibles. Although the coverage will vary from State to State renters policies will probably afford the lowest amount of coverage because it may be just a percentage of the policy contents limit. If your being told that you have the coverage and it's adequate get it in writing. Richard Siri's post in this thread offers one of the venders that will cover your collection. This has been discussed at length here before and I'm sure someone else will offer others.
Rich Figarotta R-1593
(Retired insurance agent)