I'd say since you refrigerated it, it should be ok. If it smells ok, throw it away.

Next time, just add plain vinegar to the correct headspace. I've had to do that a few times. Or I keep the extra brine and make another batch.

I'd agree that even though it is already 2 months old it is probably safe to eat - assuming you used a safe pickling recipe with sufficient vinegar in it to begin with. Some sources recommended max fridge storage of no more than 6 months.

For future reference, don't process a jar like that. It leaves far too much air in the jar. It is easy enough to make up additional brine that is at least 1/2 water and 1/2 vinegar to fill the jar to the proper level.

Dave