I think you are off on that last post. I have a early 88 with square vents and they didn't change the flange style till a later year. I could be worng. But I am sure that I have an early 88 with square vents and the compartment in the center section of the dash.
1988 was a changeover year for the Samurai - there are two possible driveshaft flanges for your truck. Crawl under there & see if the bolts that hold your driveshaft in have 14mm or 12mm heads & we can see about helping you find a replacement. I probably have an extra of either style for you, but you might not need a whole driveshaft. What is wrong with yours?