If you remove the rear sight assembly, you'll find holes there already drilled and tapped for a scope base. A $7 dollar Weaver base would do the job. It comes with all the screws you'd need. Many new Smiths include this Weaver base from the factory.
If the DeltaPoint Pro won't attached to a Weaver base (most dot sights of this type do, as a default) you will need to get go to Leupold for a Weaver style adapter plate that attaches to the bottom of the Pro.
It's possible to pay way more than $7 for a base. There are some really nice ones out there, less obtrusive and position the optic lower, but they sell for $60 plus. I'd try the Weaver first and see how you like it. Think about upgrading to a fancy base later.