Caravan LED road light issues

We purchased a brand new 2021 Swift Challenger X 850 in May this year. The caravan road lights and habitation lights are all LEDs in line with government requirements replacing the less efficient and polluting traditional lamps. After coupling up at the dealers we checked the road lights (including indicators) were working correctly. We drove off (in our Land Rover Discovery Sport) and at the first turn noticed that the Indicator Repeater Light was not illuminating. When we got home we again checked the lights and the indicators were working correctly but not the repeater lights.

Consulting the Swift website we discovered that this is a known (to them) problem. The current drawn by the LED lights is not sufficient to make the repeater work in most modern cars, the solution is to purchase from Swift, and fit to the caravan, a Sargent designed module costing about £41. The fitting instructions were easy to follow, all connections were simple plugs, and it cured the problem instantly.

My only problem now is that of spare lamps. I believe it is a requirement in most countries to carry spare lamps for caravan road lights, I have always done that, but how do I source spare LEDs when there are so many different lights on the caravan?