Terry.
I know this confuses some.
Enter 29618 into the search page. This will take you to N29618 and invite you to add another N29618.
Accept this and fill in the first profile page and when you get to the second profile page after entering the confirmation code, correct the registration in the box at the top (delete the N!).
The interesting discussion to identify the airframe makes it all the more worthwhile!
Malcolm.