You and I have communicated before some time ago.Our lines are different Casner lines.I too have had difficulty in tracing my line because of the spelling (present day descendants spell the name Casner/Carsner/Carsoner - yes all three ways).
It seems you've gotten your line back to NJ.You are correct in that many of the Casner came out of PA and spread from there.In studying immigration into the US, it seems that many people came in thru Ellis Island (NY) and the Port of Philadelphia.NY was such a horid place to live that many went on to PA.The Germans were an industrious people - farmers.They would buy up run down farms and make them very prosperous in a few years, then move on to new lands.When they arrived in a new location, the first thing they did was to build barns for their livestock (they knew they had to protect them in the harsh winters), then they would build a home.
My Casner line also came out of PA into VA, then on West.
Now to the spelling of the name!I have found the spelling pre 1800: Kestner, Kastner, Kistner, Krischner and other variations.Around 1800 it started to evolve into Casner, Carsner, Castner, Cosner, etc., etc.
The Oklahoma State Genealogical/Historical Library has a book with many, many Casners it in that arrived in PA.As I recall, many of them were in NJ.Unfortunately, the library is in the process of moving into a new building and is closed.It won't reopen till the end of April.Then it is going to be a matter of learning where everything is when I get to go back to it.
I track several Casner families (some 70 FTM files).The one that I keep track of your line is #008.If you will get back in touch with me sometime in May, I will be glad to go to the library and look at the book to see if your line is mentioned in it.But please give me db#008 so I won't have to hunt it out again.
In the meantime, could you send to me by email you family group sheets of your Casners that you have identified thus far.I will check my misc papers that I have on the Casners (I have a bunch) and see if I have anything thatyou might not have.