Tossed Salad,
I just saw what you said about being able to press both the DDV and CS to get inflation. This works for me too and I bet for all others. This would not indicate anything good because a CS leak is considered unfixable. However. I do not really think CS is the one that leaks. Let me explain.
The glans and CS proper are connected. CS is drained by the bulbourethral vein (BV) (the one which cannot be ligated or embolized). The glans is drained by DDV and BV. So, having a leak in either DDV or BV will likely cause both to deflate.
Now, when you say that you can press on the CS to get glans inflation… you need to see are you pressing on the CS or the whole penis, just from the underside. It is hard to occlude just the CS so I bet you are “squashing” the whole penis… which again only exerts pressure on the DDV. This is why I believe that the centre of our problem is the glans-DDV point. Namely, the glans is letting the blood escape into the DDV all to easily.
Sorry for all the technical talk. I really hate philosophizing because we are reeeaaaally tapping in the dark here. Its so pointless. And there are tests out there people, and experts with decades of training in problems of this kind. :)