If you can find the other mating molex, that would be neatest to connect to the monitor.
For the vga connection, you might look for a vga cable and cut one connector off.
The DB15 vga connectors are a pain to solder, specially since the rgb cables are 3 coax cables.
An old defective vga monitor can function as donor for the cable as well.
Usually, european cabinets using these monitors had a large transformer that converted the 240V to 100V.
It also provided isolation between the mains and the chassis of the monitor.
If I remember well, the Sanwa doesn't need an isolation transformer, but you might check the manual to be sure.
So, if no isolation transformer is needed, you can connect it directly to mains if your mains has the correct voltage.