RE: OS 10 Question
The spinner size is determined by the model you use. You choose the spinner and the nose of the model fairs smoothly together. As far as propeller is concerned, you can use a 7 x 4, 7 x 6, or even an 8 x 4. All will work, but you have to select the propeller that makes the airplane fly well. You get spinners and props through your favorite hobby retailer.
If you send us an email, we may be able to locate an old instruction sheet and send a copy.