Welp thats one shitty puzzle, with a nice image

Tipps:
The sevens touch the corners
there are 3 1 wide and one 3 wide line going from bottom left to top right
its all symmetrical
from there it should be solvable
if not:, the 2s (C and R 25) are on 13-14.

Agree - impossible to start. But once I got going (thank you Gewehrdalf) I enjoyed it. thanks.

Very nice, thanks for hint.

Very good. Thanks.