Mad Honk 

My experience with rims is that they are almost all put together with a steel pin between the two ends being joined together. Even those welded together. So my assessment is that the rims are not unsafe, but may not have a smooth braking surface. For that reason I would contact the manufacturer. When breaking rims apart for recycling there is always a steel pin holding them together. Using a rare earth magnet will expose the pin in the joint, so get one, they are around for next to free, and put it on the rim joint. That will tell you if it is safe to ride. Smiles, MH