I found a method that seems to work fairly well, and gives an accurate-enough looking camo net.
I have also used the camo net on the deployed guns, but only around the barrels. For the limbered guns, both the gun barrel, and the breech area get coverings. (Historically, I claim camouflage and travel cleanliness respectively. Honestly? I didn't want to have to sculpt detailed breeches on the guns!)
As a bonus feature
Here's what a Firefly VC looks like with this camo net concept applied. This was the first attempt, and you can see what happens if you use a rounded tool to push the net into place (over the front hull where the machine gun was removed.)