An update ...
I saved my .kwl files to another directory, with the plan to use "File/New Wallet ..." for the same names, close the app, remove the emptied files, replace them with the original files, and reopen the app. However, selecting "File/New Wallet ..." does nothing: no dialog, no action. Selecting "Settings/Configure Wallet ..." brings up a dialog with "Select wallet to use as default", with an empty combo box. I hit "New ...", then entered in the old file name for the .kwl file (minus the extension), then hit OK, but the combo box is still empty.
If I attempt to drag one of the wallets from konquerer, I get the warning ...
That wallet file already exists. You cannot overwrite wallets.