It looks like the OP just wants to go back to the original '91 tails.
Has anyone checked the price of this stuff lately, check out this page:
http://www.ebay.com/bhp/mr2-kouki-tail-lights Assuming the
center garnish/reverse lights mounting brackets, and later model lock come with the 'Bathurst' lights, $370 changeover may not be too bad a deal. A PITA to fit if you don't have those.
But another thing to think of is that the wiring plugs don't match so you would need to swap over those too.