The factory design was direct soldered, with often 2-3 wires in a single hole. When I did these I added a few extra holes to allow just a single wire per, and then did the size/spacing to allow the molex connectors.

So soldering the wires directly is far far more common, and closer to original, the molex connectors are an option if you want to go that route but are by no means required.

I'd avoid using the right angle connectors though, as they may potentially interfere with the reset plates. Length is pretty critical in some machines, depending on which reset plate was used. Williams had a few different versions.

-Hans