You can ask for whatever you like, including what you say above.
It depends whether you want ongoing income or the usage to stop.
If you s my client a letter personally, I would tell him to ignore it until such time as you had spent money on a solicitor.
There is no reason why you cannot send it yo, but a solicitor's letter will make them take more note.
A solicitor would probably want at least £300 for opening the file and writing to the offender's and receiving their replies.
You can of course write your own letter and then issue proceedings in the County Court If they do not do what you have asked for .
The fee for using such an image varies and can be from £25 up to thousands of pounds depen depending on the resolution of the original, your fame and the value in your image.
unless you are a celebrity, it is going to be at the lower end .
some pictures are licensed for annual use and some are purchased from the image suppliers on a one-off basis .
I would probably ask them for £500 on a one-off basis.