Treat it like you would Holga shots, know its not the highest quality and have fun with it. If anything comes out it's a bonus.
I've shot some very old 4x5 IR and got some very interesting results, though with a smaller format thats going to be like shooting through a gravel pile.
I agree with the above comments -- HIE is almost certainly toast after room temperature storage for at least 7 out of 27 years. All it costs is time and some chemicals to try it, but don't expect anything.
The Tri-X might still be usable, though it likely has high fog and will require about one stop of additional exposure above the original rating. The good thing is, you can shoot a couple sheets and try it, and if it's okay, then you'll know what to expect from the rest of the box.
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