Good to hear that you're enjoying your CB1100!
The shield pictured on my bike is a National Cycle Street Shield which I really like. Once mounted and adjusted the first time it goes on and off in a minute or two. It blocks the wind off my chest, I get light wind at my arms and helmet but no buffeting. It is 16"W and 17" tall. They offer a Street Shield EX
that is a little larger but not so large as a Plexifairing 2. The EX is 19W x 18" tall.
I'll also add that I had a Corbin made for this bike and it came out well IMO. I didn't care for Corbin's pleated stitching nor the incorporated backrest hardware on their standard offering for this bike, I wanted it to look more like a stock seat. In essence it moves you back about 1 1/2" and the seating surface is 2" wider and no forward slope so it's literally all day comfortable now.
Stock seat is about 9.25" wide but only at the very back.
Corbin is 11.5" wide from the step forward a few inches.