Can anyone please shed any light on how to fit one? I bought an early body that has one missing, ordered up a replacement from Nikon Spares but am struggling with fitting it. The F3 repair manual which doesn't help a great deal & suggests that it should just push into place. Once inserted & pressed, the exposure lock function works OK, but as soon as I tilt the camera, it slips straight back out. I have seen suggestions online to put a bit of glue on the end and that the early bodies need to be stripped down to fit it. Can anyone shed any light? Thanks.