I have a small oil painting that I have taken to a few "art experts" in my area. I have been told that the painting is either 100 years old and worth around $100, or that it is more than 300 years old and worth thousands. I would be happy to provide pictures by e-mail and answer any questions to begin with and decide the logical next step based upon expert determination. Any help would be appreciated.

On-line appraising is a very dodgy business, not because people are dishonest, but even an expert needs to have the item up close in order to get a feel of it.
You can search the web for what seems to be reliable auction-houses and contact them. That´s always the best bet.