Howdy Dave,
First, let me welcome you to the forum, we are glad you found us.
Ok, now onto your problem.
go to:
http://www.revell.de/en/company/contact/index.html and fill out the form provided.
Inform them that you own a 1/32 scale model of an F 15 Eagle, include the stock number if possible, and explain what you are looking for. Then also let them know that you also own a 1/32 scale model of the tornado, include the stock number if possible, and explain what parts are needed for that kit. If at all possible, give the part numbers from the plastic sprues or instructions for the pieces needed.
Now, they may charge you the cost of the part, and/or shipping and handling, but since you are looking to purchase the parts anyway, this should be alot cheaper than an aftermarket retailer.
I hope this helps,
Have a good day,
Greg
PS, the kit stock number can be found on the instruction sheet usually