1969? Easiest might be to re-use your existing connector by soldering wires to it's and covering w/ heat shrink. You could also re-use your connector housing and use new "flag terminals". They are a "Packard 59" type spade, as I recall and are thicker than the "Packard 56 terminals" used elsewhere in your car.
In my 65, I didn't like the gnd eyelet at the bulbs, so ran a dedicated ground wire back to a solid gnd junction. I suspect a bad ground is the reason for many weak headlamps in pre ~1973 cars.