A few things come to mind. First, verifying you actually have the OEM shifter bucket AND Indicator plate, be sure the lamp sliding portion moves freely back and forth in the indicator plate. Sometimes there has been some melting of the plastic (heat from the bulb). Repair as needed.
Shifter linkage to the trans should not be connected yet to help assist in these adjustment steps. It CAN be, but having it connected might cause unnecessary errors in adjustments.
Index the plastic studs into the metal stands of the shifter base. And snap the plastic linkage rod in. I have used the repro ones successfully (usually reprod are made of black ABS plastic, originals typically are white) Be sure to lay the wires out in a fashion that allows for free movement as you move the shifter from Park to Low1. (NOTE: The two wires should roll freely back and forth, much like the ribbon wiring that you might see on the ink cartridge of an inkjet printer).
With the console NOT in place, check alignment of the indicator. If it is off, bend the metal stands of the shifter bucket forward or backwards as needed till the indicator lines up. Check function from Park to Low1 repeatedly. This last step you might need to finesse the metal stands a little. Put the console in, secure console with all mounting screws and recheck alignment of lamp. Ideally, you should be good to go. If minor adjustments are needed at this time, a little effort might be needed to move the indicator plate fore or aft, using the slots in the console base.
*NOTE: These steps should work if your dash panel is where it should be and the hole for the shifter is where it ought to be. If your car has been wrecked hard or reconstructed with repro parts, all bets are off for these steps solving any issues.