First of all, Leif, thanks for the opportunity. I've gone ahead and for the first time in too many years read all of the combat chapters in the original PHB and DMG. It is, as you say, a very elegant system. Plus I love Gary's prose 
As to magic items:
As a 4th level character, there is a 4% chance that any item he does get is +2 instead of +1.
Shield: 32%
Chain mail armor: 60%
Protection Scroll: 20%
Dagger: 40%
Sword 36%
Bow 20%
Potion 28%

As to magic items:
As a 4th level character, there is a 4% chance that any item he does get is +2 instead of +1.
Shield: 32%
Chain mail armor: 60%
Protection Scroll: 20%
Dagger: 40%
Sword 36%
Bow 20%
Potion 28%