Pens are not flat work or furniture. No need to use 120, 150 or anything less than 320. I can see scratches that were filled in some by CA.
The spots not filled in is because of using thin CA and applying it with Paper Towels. Thin is OK in many cases, but where grain and capillary indentations are at play, use medium or thick. If you are using paper towel, then you should apply more CA and in thicker layers. Remember, you paper towel is going to absorb at least 75% of your CA, so you are not getting nearly as much as you would think.
There are methods of applying CA so that 90% - 95% get on the pen.