I own a Volvo 1973 145, and a 1991 245. It’s interesting to me how little the tailgate has changed (which to me means: has needed to change) over the years.
A big modernizing-look style change occurred when the shapely chrome handle such as on my 145 was replaced by a square, matt black handle such as on my 245.
I recently analyzed a 1983 245, and discovered that its shapely chrome tailgate handle looks the same as on my 1973 145.
The tailgate hinges, on the other hand, were still chrome until at least 1991, and quite possibly after that too. I have yet to analyze a 1993 car, to make sure.
The tailgate struts and attachment parts seem to be identical through 1991.
The lock and wiper mechanisms, however, are different on the 1983 vs. 1991 cars.
The 1983 car has its washer fluid nozzle on the side of the body; the 1989 and 1991 cars that I analyzed has them at the top center, with a hose running along the top of the tailgate lip to feed the fluid to the nozzle.