re-rendering roughcast

[Maja]

I would like to re-render a part above my window. This is a new patch done by the previous owner and I can see that it is of poor quality compared to the new one. I would like to call the plasterer during springtime to re-render that patch. I know that the color will never perfectly match the old render. I was wondering is re-rendering possible considering that it is roughcast and what would be the best approach to this issue?
Thanks!

 

[Alastairreid]

Thats a poor patch, you can get a better patch but it will always be a patch.

 

[Maja]

Thats a poor patch, you can get a better patch but it will always be a patch.

I know. It will never be perfect, but what do you suggest to improve it? I can not render the whole wall from above as the first floor is the property from my neighbor. I can only expand the new render above the whole window and below the window.