You are not copying everything entity has, especially for trains, which have names, stations, interrupts, colors and other settings, that are lost.

Try placing down ghost of a quality locomotive that was copied from existing locomotive with customized settings. You lose everything due to not copying everything needed:

local info = {
name = entity.quality.name .. "-" .. entity.name,
position = entity.position,
quality = entity.quality,
force = entity.force,
fast_replace = true,
player = entity.last_user,
}
entity.destroy()
surface.create_entity(info)