Looks like an SA belt & buckle to me- depending on size. It could be a HJ if smaller than normal.
I think its looking like an early SA buckle, but the eagle looks strange and the swastika seems misshapen, im not 100% sure its genuine, wait for more comments
As said - I too think it's an SA buckle. I think it's legit. A picture of the back of the buckle would certainly help!
I'm with the guys...an SA buckle that looks good and the design is a known one shown in the "SA Mobile Swastika" sticky thread. That being said, the roundel looks a little odd to me, especially on the viewer's left as the there's a lot of brass showing (worn?) and the roundel is supposed to be nickel/silver. Perhaps the photos? As Rob said, a photo of the reverse would be helpful and for me crucial before a purchase.
I agree with the rest, original buckle but pics of the rear would confirm this