How to restore values of default VPC Security group within a given availability zone?

I am operating in US-West Availability Zone. I was trying to solve the problem for ELB and I courageously or stupidly changed the Source IP of my default VPC security group to fix it. It did not fix the original issue but now I am in to another issue.

Now I am trying to restore the default VPC security Group setting in my Amazon Web Service account.

As per my knowledge the default VPC is very restrictive. I don't quite remember what was the value for inbound source IPs. I changed the Source IP to Anywhere (0.0.0.0/0) in the default VPC Security group on AWS Console.

So how do I bring back the original default VPC security rule inbound IP setting that is applicable to my availability zone?

What is the implication of this? I have not used default VPC on any of the EC2 instance or ELB.