So I have created many 256x128 .png images to make my own billboards around SA. The only problem is finding the precise file in txdworkshop to replace which is very time consuming. And its kind of trial and error hoping you are changing the billboard at the location you want to change it. It really sucks *ss, I don't suppose there is a easiser way of finding what you're looking for in txdworkshop?
*Sighs* Doesn't matter I am now working on a table of all the .txd files which contain billboards which I will publish to this site once I am done. Also I will be working on some 'idiots guide to modding' as I am having difficulty understanding the basic of modding for SA due to the lack of clear concise tutorials that aren't littered with tech jargon.