Hi Tony, thought this might be of interest to you..
This is a section of my Abracadabra that i did a few years ago. i did this webbing using the toothbrush method.. dipping the brush into black enamel paint.. straight out of the tin, no thinners or turps used in the paint. Just scraped the bristles with a icypole stick, about a foot away from the cab ( i tested this first onto cardboard before trying it on the cab!!)
Thinning the paint gives small dots like what you see on most mid 70s cabs. Using the paint straight out of the tin, it was thick enough to go on real "stringy" as the pic shows.
Hope this is of some use to you, or anyone else who might be interested to try it.. but test it on something else first!!!
Cheers... Mitch