Hello Ed,
Yes, both of my ver 1 Falcons only have the one screw holding the booms to the stab.
I just added a washer to the equation and it has been fine. My experience is that there isn't a lot of load on that area so I added the washer to stop the screw head from pulling through the balsa skin.
Your idea is very neat and would be a worthwhile mod if I were doing another one.
Col