That's probably true. But they wouldn't match other existing NJ Skulls (or Desert Sands), if wanting to expand a current set, or wanting to later sell to somebody else who owned originals.
Very true - they won't match. You'd need to ensure that you would never need to add-on to it later or sell them to someone else. I'd never go this route unless I was going to sell my set and start with another one. However, since @Lototo is starting with nothing, this could be an option.
If a magic genie said, "Hey, I can snap my fingers right now and you could have your NJ Skulls on the same type of blank that your DDLMs are on", I'd take it in a heartbeat. My set doesn't need expansion and I'm never letting it go.