I have say 30000 files of this type: picture.jpg.~12~
They are remnants of a backup (mv -v --backup=numbered ...).
I needed to switch the extensions to: picture.~12~.jpg
I have found this solution finally which might inspire you in This Long Dark Covid-time of the Soul.
ls *~*~* | sed -n "s/\(.*\)\.\([^.]*\).\(~[0-9]*~\)$/mv -v --backup=numbered \"\0\" \"\1_\3.\2\"/p" >switch_extensions.sh
chmod +x switch_extensions.sh
./switch_extensions.sh > switch_extensions.log
The first line produces commands:
mv -v --backup=numbered "Trombone.tif.~10~" "Trombone_~10~.tif"
The second line makes it executable, the third is renaming while creating a log file. Then swiftly comes relief from the dark soul ruminations. Try it!
You might know a smarter solution, so let brains storm! :-)
mmv '*.jpg.*' '#1.#2.jpg'