Thank you very much, gentlemen!
I know where I can find the Aires models, I think I'll buy them.
Here is a picture, to show you the twin 050 in the Revell box :
http://www.hmsvictoryscalemodels.be/PT117/photos/photo17.html
I have a PE set by White Ensign Models, with air cooled jackets, unfortunately instructions ask you to to adjust them to the parts found in the box. Sorry, but the Revell parts for the .50 are so incorrect, I do not use them. With so small models, it would have been better to have a good resin or metal shape to put the PE parts on.
Thank you,
Michel