From what I was able to find there are two versions of the Big Daddy. One had you attaching the shock cord to the forward centering ring and the other went with the standard Estes BT mount. I read through the instructions on the one I built, which had you gluing the mount to the BT, and decided to skip both methods altogether.
I wrapped some picture hanging wire around the motor mount right up against the aft side of the forward centering ring and then ran it up through the forward centering ring. I reinforced the area of the centering ring that the wire passed through with a scrap piece of balsa glued flat to the centering ring and extending from the motor mount to the BT edge of the centering ring. The balsa is flush with the end of the motor mount. A picture is worth a thousand words though so I have attached one.
It's a very sobering feeling to be up in space and realize that one's safety factor was determined by the lowest bidder on a government contract.
— Alan Shepherd
I may be drunk, Miss, but in the morning I will be sober and you will still be ugly.
-- Winston Churchill