The lock on the tailgate of my '91 Defender 90 locks as normal with the key but can be unlocked with a 5p coin. In fact I've tried unlocking it with my fingernail and just about managed it.

Strangely, I can't lock it with the 5p - it actually needs the key for that.

I don't really want to change all the lock barrels as the others work fine and I only really want to have one key if possible.

Before I pull it to bits, has anyone overhauled a lock barrel like this - or is it beyond redemption ?

Check out the lock kits on ebay and elsewhere the're not dear and not too hard to fit. It will sort your problem and allow you to stick with one key.

If you do take the lock apart make sure you keep the key inserted in the barrel or its a right ball ache to get it all back together. I'd say it just needs a good clean.

Thanks - I'll give that a go first