re: Storing Pickled Eggs

I can't help with a source for jars in the UK, but I can help with the safety issue of pickled eggs.

For safety reasons, pickled eggs must only be made, left unsealed, and kept in the fridge, never at room temperature. There have been reports of botulism from improperly stored pickled eggs. The eggs need to be kept completely covered by the brine, too. They can be kept in the refrigerator for up to 2 months.

Any food needs to be thrown away if left at room temperature for more than 2 hours.

There is no way to safely can pickled eggs at home. The processing time needed would make them very tough.