The older ones without the LVC look the same as the later models that have it. You can e-mail Novak with the serial number, little white sticker on the side of the case, and they can tell you if it has LVC or not. Give Novak Two a day or two and he will confirm or deny this

There is no way to tell by "looking" at them.

This is assuming that by "safe" you mean it has a Lipo Cut-off, you can run
2S lipo on any esc that will run on 6-7 cell nimh/nicd. The LVC is the only reason some say not to run lipos on certain esc's.