your car is actually almost 25 years old

.....making the parts issue even worse.
I find that the online catalogs from infinitipartsdeal and some others are actually pretty helpful.....only because those will show you the original (or perhaps current) nissan part number--even for a discontinued part.
Then you can go hunting.
I have found many (not all) parts are still available in Japan, so perhaps that is an option for you.
check out amayama trading (you must know the part numbers!)
remember if you go this route YOU become the importer, which means you may have to pay tarriff (10% for Japanese auto parts) depending on your import $ amount.