Those seems to be hidden, much like the UL Meet & Greet welcome booth and the utopia drooping flowers (which give dew). That means you'll need a mod from them to show up in the buy mode catalog. There are mods available for the booth and the flowers, but I didn't turn one up for the legacy statues.
If you want to pursue this yourself you might be able to clone them with the S3OC (Sims 3 Objects Cloner) available on the simlogical site. I'd think an override instead of a cloned version might be better, but I don't know how to do that with S3OC. The creators/modding forum at MTS might be able to help you out. I'm not aware of any S3OC tutorials unfortunately. My experience with that program is rather limited.