yes i think its for sure modern. I work in marine construction. Its not stainless obviously and if it wasn't galvanized that thing could be 5-10 years old, just from ground water. I have seen bigger galvanized ones looks far worse in 5 years in seawater. it wouldn't take long if it was just plain steel in the groundNot a chain expert but I’d agree somewhat modern. from what I understand older chains had longer links… of course always exceptions