Not saying that what you made won't work but, you still have a lot of real estate blocking airflow. If you look at the quality aftermarket products, they provide protection, without sacrificing cooling. Here's what I have on mine: EvoTech (look at how much "empty" space there is to flow air, with the holes being so close together, compared to your current set up).
2007 Honda VTX 1800C
Sold everything else
If you have the time, you could make the existing holes a little bigger. I think it looks better than the store bought ones by a mile. Nice work. Also you could use something to hold the grill off the rad by another 1/2" (washers, high temp rubber grommet,..) and get some flow around it as well.