French 441 is very similar to the UK 405 line system, both having +ve modulation.
A few of us use a PC with a suitable graphics card and use the legacy Modeline instruction to create the required TV waveform.
Modeline "405i50" 8.10 664 680 752 800 377 378 385 405 -hsync -vsync interlace
creates a native 405 line picture on my Cossor 405 line set
Changing the modeline to 441 lines as suggested by forum member Semir_DE
Modeline "656x383_25 11.0kHz 50.0Hz" 8.820 656 665 744 800 383 384 392 441 -hsync -vsync interlace
And a slight tweak of the horizontal hold from 10124 to 11025Hz and we have a locked 441 line picture. No expensive "system converter" in sight, and it doesn't require my source material to be in a particular analogue format.
Running a rare historically significant set on the wrong standard seems almost sacrilegious to me, but perhaps I attach far too much reverence to these old sets.