I remember those, and they worked well for carry with a pancake holster. That what was issued for concealed carry when wearing a blazer.

As far as belt size I have never had a problem no matter what the thickness of the belt. Inner belt size is pretty much waist size at belt loop level. Outer belt is usually 4 inches larger. IWB carry inner belt will be 4 inches larger.

Belts are measured from where the buckle connects to the leather. Depending on the buckle an extra inch or more of length is there to take up for extra thick belt. Go to a large rodeo buckle, and your going to gain 4 inches.