Yellow/bk should be the low beam. If you can find a 56b on the light, it may go there.
Brown is ground, if there's a 31, try there.
Bk/Wht should be the left signal,
that ought to leave Ylw/Green as the marker light.

You may need to open up the light to trace the pins correctly. You can use the meter to check:

Lights off = nothing

Ignition on, left signal on = blinking +12 on Bk/Wht and brown
Marker on = +12 v at Ylw/grn + brn, 0 at Ylw/bk + brn
Lows on = +12v at YLw/grn +brn, +12v at Ylw/bk + brn

I think the "new" lights are actually euros and not DOT (or canadian spec?). The H4 bulb is a superior bulb. Resale will be higher with the euros. I'd put them back in.

This may explain why you didn't have front marker lights. If your dad converted, but didn't adjust from DOT to euro wiring, they may have dropped out. There ought to be a plastic housing on those sleeves, BTW.

Or I'm sure someone would be willing to accept the euros for a W115 for a small fee.