Datsun Roadster & Fairlady Early Battery Hold Down Frame OUT OF PRODUCTION
65 - 67 Powder-coated Battery frame
No this isn't a Nissan original part and it never existed until now. The Nissan original is the simple strap in the LH side of the photo. If Nissan new in 1965 what they knew about battery frame construction and stability in 1967, they probably would have rendered something that looks like this which is how all later Nissan frames are constructed. They didn't do it so we'll do it for them 40 years later.