Goto this Page and look for content you would like to migrate to the current wiki. (OpenVPN-stuff for example)
The articles are there for a reason: We do not want to delete them, but we also cannot put them into the current wiki, because they reflect an old OpenWrt build. Things are done differently (and much more easily) on the current OpenWrt-Installation. For example, we do not use NVRAM any longer and also, a lot of software is available in package form.
Start a new article and get inspired by the old one. Keep in mind that the current wiki is highly modularized: