Hi again,
Excuse me for the long silence! I was trying to make a better processing of the combined data. The second session was less productive... Worse alignment gave only 40s exposures. Also I didn't succeed to orient the camera by the same way, so had to limit the FOV to the biggest possible intersection and sadly NGC 5474 is out of it...
This is the result from around 1h and 25min total light - 50x50s + 53x40s + 9x45s + 1x55s + 1x60s; 45 darks (matching exposures); 40 bias frames. Everything is with ISO 1600 and taken with APT. This stack was made with MaximDL (didn't manage to get usable result from DSS

), and then there was some processing in PS.
Definitely I'm satisfied with this image

This week is rainy here, so maybe will play a bit more with the processing