The Lewis needs spare drums, because there are not so many rounds in.
The SE.5a hat one spare above the instruments and another below the the seat, the Sopwith Dolphin some drums below the seat.
The Bristol Fighter had spares on both sides of the cockpit.
The landing lights was Holt flares, electrical ignition, but then magnesia burns very bright. Please see the recent build report of my SE.5a night fighter.
Cheers,
Frank