Mate,if you've got any broken 2413's laying about,their a perfect press fit over an 11/32 Cedar.
I use then to foot my Cedars so I can shoot 3 blade thunderheads.
The fit is very tight and I taper the edges of the cedar to get them started,then just tap them lightly home with a very small hammer.
I've recovered heaps of 11/32's that have broken off just behind the field point or glue on broadhead,so you could probably use the same idea to extend your Cedar shaft a few inches.
Good luck.