Inner plastic seals never opened on recent manufacture kits, the vintage kits never had inner seals to begin with.

1) Monogram DeHavilland Mosquito  1:48

2) Monogram Spitfire Mk IX  1:48  vintage kit 

3) Monogram Hawker Typhoon  1:48

4) AMT Zero A6M5  1:48

5) Testors Me-163 Komet  1:48

6) Polish  PZL  P11c  1:72