Steve, if you sell it, I would put it on E-Bay. Certain distributors have very desireable numbers and dates and can bring big bucks (Boss 351 distributors are routinely over $1,000). You might call Distributor Dynamics in Cal and talk to Chuck. He can tell you what you have and is very honest in my experience.
Now if you keep it and drop it in your car. Block off one set of points with the cover of a match book and set the dwell to 26-27 degrees. Remove the match book cover and use it to block off the other set of points and set the second set to 26-27 degrees. Now put the cap on and start the car. You should find you are right at 30-32 dwell and good to go. They should run great for thousands of miles.
I will say this though, if you are not running a hi po motor, you probably don't need the dual point and while setting the points is no biggy, swapping the distributor can be a nightmare (as in, the rod to drive the oil pump drops out the bottom of the distributor as you are pulling it out and drops down into the oil pan. Oh boy, that's fun). If your car is happy with the current distributor, I would stick with it. Just my 2 cents.
Jeff | 
Setting the points isn't a big deal.Just rotate the motor by hand from the crankshaft until a distributor cam lobe is straight against the contact point of the points, set the gap to spec and repeat for the other set of points.If you decide to sell it I know a couple of guys that are looking for nice one.If you like I could get there phone numbers for you.Hope that helps.
