I know nothing about Nivada, sorry.

But you do find Nivada NOS (New Old Stock) watches on eBay from time-to-time and this is what this watch is.  Came complete with tag and original strap. I rather like the clean lines of this watch and the screw-down back is gorgeous.

Houses the fairly common ESA 9150. This wasn’t working when I bought the watch; the big brown condenser by the stem needed replacing; working fine now though — look at that balance go!