Mister VGA to SCART cable with proper CSYNC attenuation
This is the wiring I use to connect my Mister FPGA with my CRT TV with a Rankie HDMI to VGA adapter:
Pin 14 from the VGA connector outputs the Blanking signal at an adequate level to activate RGB mode on the TV and is connected to pin 16 of SCART. Pin 8 at SCART is left unconnected; this avoids 16:9 mode gets activated on some TVs as explained here.
The HDMI to VGA converter outputs 2V CSYNC so you'll need to put a 470Ω resistor in series in order to attenuate the signal below 1V as the SCART specification requires.
This resistors along with the 75Ω termination resistor in the TV forms a voltage divider that attenuates the signal to ~400mV. I've verified this using a cheap DSO150 osciloscope.