I have not done a FTF for rifles in over 10 years, but with the current climate in this hellhole, the statutes are confusing. Can I still do a private FTF transfer on long arms without an FFL
in this State to a person not related ?  Both of us have our FID cards.

Thanks in advance.

Nope - must go through an FFL.

ETA - statute 2C:58-3b(2):
A person who is not a licensed retail dealer and sells, gives, transfers, assigns, or otherwise disposes of, or receives, purchases or otherwise acquires an antique cannon or a rifle or shotgun pursuant to this section shall conduct the transaction through a licensed retail dealer.
The provisions of this paragraph shall not apply if the transaction is:
(a) between members of an immediate family as defined in subsection n. of this section;
(b) between law enforcement officers;
(c) between collectors of firearms or ammunition as curios or relics as defined in Title 18, U.S.C. section 921 (a)(13) who have in their possession a valid Collector of Curios and Relics License issued by the Bureau of Alcohol,Tobacco, Firearms, and Explosives; or
(d) a temporary transfer pursuant to section 1 of P.L.1992, c.74 (C.2C:58-3.1) and section 1 of P.L.1997, c.375 (C.2C:58-3.2)

Does immediate family include both sibling-sibling and father-son/son-father?

n. For the purposes of this section, “immediate family” means a spouse, domestic partner as defined in section 3 of P.L.2003, c.246 (C.26:8A-3), partner in a civil union couple as defined in section 2 of P.L.2006, c.103 (C.37:1-29), parent, stepparent, grandparent, sibling, stepsibling, child, stepchild, and grandchild, as related by blood or by law.

So yes, both of those scenarios would be covered for a private FTF-transfer.  Note that the FID and CoE requirements remain in effect.

Back date the COE?

Clever.

As long as you have copies of the old COE....just sayin'  

Relax, I don't do stupid shit, I'm a wise old man

I would never take possession of a back dated COE from someone I don't know. You never know if there is a body somewhere tied to it. Especially from someone who lives in the boonies near the Delaware River.

wasn't there just a story about a guy who murdered someone and buried them in the Pine barrons?  I spend a decent amount of time in the pines and have always thought about stumbling across a body.  I have found other things such as devil worshiper things

Check your IM