I used 2” painter’s tape to hold the display in place, but did it a little differently. With the wedge holding the iMac at an angle, I laid the display in place and felt on the sides to make sure it was centered. Then I put small strips (4-5” long) all along the sides and top, wrapping the tape around to the back of the display to hold it in place. Then tested my repair to make sure everything worked.
I had seen some comments about problems with the strips holding in place over time, so I didn’t actually install them. Instead, I’ve left the painter’s tape on mine. I’m a week or more in, and so far there’s no sign of failure to hold. I’m going to leave it this way until I decide whether or not to replace the blade and hard drive with an SSD. I find I don’t even notice the painter’s tape as I’m using my iMac.