The Argus pulse jet is not much more than a tube with an atomiser at the front end so for the most part there is next to no detail to be seen anyway.
![Image](http://www.zenza.se/vw/vw%20bilder/vw0269_b.jpg)
I have looked through my Monogram Close-Up number 4 (I knew it would come in handy one day) and there is no mention of the tubes interior colour in the official painting documentation, nor do any of the war time photos clearly show the tube interior as most are shot from the front and not the rear, those that are taken from the rear have the tube interior in shadow and thus I can’t even guess at what the correct colour should be.
But the following image suggests it may just be bare metal (which make some sense) or even perhaps indeed be light blue.
![Image](http://www.zenza.se/vw/vw%20bilder/vw0261_b.jpg)
You could try and get a copy of Osprey's, V-1 Flying Bomb 1942–52 Hitler’s infamous “doodlebug” (New Vanguard number 106) as it may have some more info, sadly I do not have a copy publication myself so i can't on if it will shed any further light onto the subject. But as I have ordered the kit version of the V1 I may just have to go out and get myself a copy.
You can go to this site for more images and info about the V1:
http://www.zenza.se/vw/
As for "obscure" supjects I say bring them on things like the Natter, Supermaine and Macchi Racers etc, etc, etc, the more the beter I say!