Easiest way is to get a new lock barrel which will come with keys. I assume door is unlocked? Barrel is easy enough to remove from inside of door. Take it out & take to caravan shop to match up. Caravan door locks are fairly standard items there are not many different makes.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.