iPhone Saving 6.0 SHSH blobs with TinyUmbrella

After jailbreaking my iPhone 5 that is still on 6.0 I cannot save SHSH blobs with TinyUmbrella. Getting this message:

For version [iPhone5 6.1.2 (10B146)] - This device isn't eligible for the requested build. 04/22/2013 16:57:56.681 APPLE is NOT signing iPhone5 6.1.2 (10B146) SHSH requests anymore. All you can do now is select CYDIA and hope that CYDIA has your SHSH saved. If not, there is nothing you can do.

How can I save my 6.0 SHSH blobs in case I need to restore my device back to 6.0?

Thanks a lot for a quick response.

Does it mean that if something goes wrong I will not be able to restore it to 6.0 and the only option would be to go to 6.1.3 that is not jailbreakable?

Intell said:

You cannot restore an iPhone 5 with saved SHSH blobs.

Click to expand...

So technically even if I saved 6.0 SHSH blobs when 6.0 was current, I can't restore iPhone 5 to 6.0 using those saved SHSH blobs?