project smaller image into a bigger one

[rich2005]

For the 'visible' layer

Crop the layer to remove the section containing the erased text
then
Layer -> Layer to image size to restore

30 second example: https://i.imgur.com/NlSeWos.mp4

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Another way, for the visible layer

Set the background colour to black
Remove the layers alpha channel, Layer -> Transparency -> Remove Alpha Channel (overwrites the saved erased pixels)
Restore the layers alpha channel, Colours -> Color-to-Alpha selecting black as the colour

another 30 second example: https://i.imgur.com/ikmPt3G.mp4