Interesting discussion in the comments below the model built of this bird. There is a strong argument that the gun barrels were nothing more than decoration as there are not the usual ejector chutes open for the shell casings and also concern that the vibration from firing the guns would have messed up the cameras.
http://www.network54.com/Forum/47751/thread/1430923206/More+F-4-1-LO+(P-38E)+FOTO-JO+Details
CBI flown bird from the 9th PRS
http://www.9th.photorecon.org/index.html
Another bird from the same unit. Obviously fake guns.
Interesting conversations wont go as far as saying fake guns at this point.
For example they look to be blast tubes or flash suppression not to dazzle the pilot when firing.
6th NFS Had them on there night fighters.
Also an option on P-51's.
When you compare the two aircraft the outer 50 cals are about the same length. Now if I was flying around with fake guns I am sure I would throw on the blast muzzles just to make sure an enemy could see I mean business, after all the two 50's on FOTO-JO are very short and the enemy would have to be very close to see them.
As a side note are these fake guns?
The question is can two 50 cals fit in with all of their hardware with two cameras like FOTO JO?
Here is a few photos I found with the doors open on recon aircraft.
Now a couple of regular P-38s.
Based off of the above photos I would say yes they could fit them with some modifications. The real question that is an unknown to me is where did the spent shells go if they were active guns?
Looking at other P-38's I see 4 ejection chutes for the 50 cals I can't find a 5th chute for the 20mm though at this point.
Is this the answer a catch can internally?
https://ww2aircraft.net/forum/threads/p-38-disposal-of-20mm-cannon-shells-and-links.24455/