Its a 71 mate. But you actually have the rear badge on the front,if you look at the back of the badge it should have a slight curve to it to compensate for the flat style tail lights it came from.If it doesnt have the curve its off the back of a liftback.
The grill will also take the italic style GT badge.I think there are only 2 different style TA22 GT grills,the one like yours that will take the current badge/italic badge and the one that takes the block style GT/GTV badges that are in the centre.
Are you sure its the wrong badge? Looks like it fits perfectly IMO.
Anyway there are 3 types of GT/GTV TA22 grills (I have a feeling there is a fourth though)
Early GT one like in the photo (has 4 badge mounting holes)
Late GT one (has 2 badge mounting holes...I think)
GTV one