D12 question, wiring for lights and switch

I'm replacing some light wiring and the light switch. Our D12 has the wiring harness for the lights cut off where it exits the tube that also has the battery cable inside, below left side of seat. I'm replacing the wiring from that point on. The original short wires from each light, with the connectors, are just hanging there loose after passing through the fenders. Can anyone with a D12 or similar tell me if there's a certain routing for the wiring I'm replacing? Any keepers or brackets that I'm not seeing? Or does it just run across under the seat? Tractor has only the fender mounted headlights, and the work/tail lamp.

On the light switch, I'm not restoring the tractor, just getting the basics working, so am buying a toggle switch locally instead of ordering the expensive factory style online. The manual calls for a 20 amp fuse (I already replaced the broken fuse holder). When looking at toggle switches, I see different amp ratings. Do I need a switch that's 20+ amp? Saw one that's only 10 amp but wondering if that means it could burn up before the fuse blows?

Any help would be appreciated. I know I can cobble this together but trying to keep it somewhat correct.

Sorry I can't help you on the original route for the wiring but I will recommend you get a toggle switch that can handle 20 AMPS. Over the years with many vehicles and equipment I've seen switches give up for lack of durability in conjunction with amperage load. It'll likely only cost $2 more than a 10 AMP would.

I did go ahead and get a 20 amp switch.
Bought some 14 gauge wire but it's got
real thin insulation, not thick and
rubbery like the original. Might be OK but
probably will be shopping for the heavier
insulated wire.