Okay. I know the thread has been inactive for a year, but I have been commuting for a lot of my time and have not had opportunity to 'play' in Slackware land.
Since I am using Slackware 64-bit, your mileage may vary. The fig2dev is not a part of WinCFG, so much as it is a part of the transfig package. Unfortunately, Slackware doesn't seem to have that package in 14.2. Never fear, our friends at CentOS have a package that can be converted using rpm2txz. For those Slackers too young to remember, we used to have to do this all of the time 'back in the day' only then it was rpm2tgz. So, go to this page
https://centos.pkgs.org/6/centos-x86...86_64.rpm.html and if you are using the 32-bit version, click on the i686 link. Go to the Downloads tab, click it and download your package. Then rpm2txz transfig-3.2.5-10.el6.<ARCH>.rpm (<ARCH> is either x86_64 or i686) and let it finish. You then do installpkg transfig-3.2.5-10.el6.<ARCH>.txz to install it.
That gets you past the fig2dev issue and on to the next.