I wasn't aware this was a traditional or ordinary design. I thought it was original since it is inspired on a poem. Anyway, I guess I got stuck with the idea that this belt buckle wasn't just a present, but some sort of symbol. Something like the wedding bands, that are supposed to be symbols of commitment, of true love. Therefore, I thought it had to be something that was close to Ennis's soul, to who he is. I got the impression that is what Ellery is looking for. He doesn't want to give Ennis a present, he wants to give Ennis a token of his love, which is different. But it doesn't matter, I guess Louise will describe the belt buckle she considers right for the plot!