Wow, a new 1989 date, nice. Dec. 10, 1989, The Loop Lounge in Passaic, NJ. There was actually some circumstantial evidence of the gig already available out there if you knew to Google for "Loop Lounge Nine Inch Nails":

https://www.loopnet.com/Listing/373-...c-NJ/20381865/
https://www.yelp.com/biz/the-loop-lo...ssaic?start=20
https://unwinnable.com/2011/08/17/wh...ll-party-hard/

As for the other new 1989 date, I've been unable to find anything online about this "375" club, other than this one video:



Possible address for the club is 375 George Street, New Brunswick, NJ, which is currently a Popeye's Chicken. In the back half of the building it has the Stress Factory Comedy Club (technically at address 90 Church St.). Perhaps Club 375 was in the Stress Factory area, or maybe the front part of the building (where Popeye's is) was a club space back then too?

What is the unsure date? I didn't see anything that contradicted any information we have on any other dates.