Oops, the sweet little P-51D, the pull-out plan with the new June 2013 issue, is missing a part. Please accept our sincere apologies. 

It's the part/s the front hatch sits on but you can download a .pdf file of the missing item - just Click here to do that. 

Apologies again. Don't forget that you can talk to designer Ton Van Munsteren and check out his build blog at the same time using the forum link below.