You have a pair of Speke's hingeback tortoises, Kinixys spekii. They're quite different from the true Bell's hingeback, Kinixiys belliana belliana.
The importation of all the species currently lumped under the "Bell's Hingeback" name, has been banned since the early 2000's and therefore, those species like Kinixys nogueyi, which was the most commonly imported species, are extremely rare in the US and sell for hundreds of dollars when available.