My latest upgrade to Viktoria is a new wiring harness for hi & low beam. There was more than one volt drop at the bulb end of the stock wiring harness so, even though I had already upgraded the bulbs, the lights were still a bit poor for my liking.
So on to ebay and bought this rather than make my own:
https://www.ebay.com.au/itm/H4-Headlight-2-Headlamp-Ceramic-Relay-Wiring-Harness-Light-Bulb-Socket-Plug-Kits/401652782355?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649
The beauty of this design is that the old light plug becomes the switching source for the relays and power comes directly from the battery. I installed it today and out of sight in the engine bay. The only tell-tale is an additional wire to the battery, all the rest of the connector, relays and wiring are out of sight. I should add that I had to run a longer wire to the battery from the fuse as the one in the kit was too short. But I was trying to hide the upgrade.
Worked a treat with full voltage to the bulbs now. Hopefully I won't melt any road signs. You could make up your own using the same design.