Difficult question, made more so because of the lack of information on the package.
It doesn't really matter as long as you stick to one method and see how it goes. You should see a drop in BG so, if you don't, reduce your carb intake.
I've never quantified the amount of carbs but have always looked for low GI foods. Consequently, I eat things like brown rice, barley, wholewheat pasta, wholegrain rye bread and so on. I will eat an apple, plum, pear etc but will think twice about eating a yoghurt with 7g or 8 g of sugar. The idea is to try and get into a mindset where selection of foods is automatic. I don't want to spend the rest of my life with a calculator in hand.
If you are going to include non digestible carbs in your 120 - 160, you won't be over eating on carbs but make sure some of the digestible carbs are also slow release. Then just monitor your BG levels over a period of time and reappraise the diet later. Everyone is different anyway so you don't 'know' how you will react until you try. These things are only guidelines.