Kit availability shouldn't really be a factor. As long as the procedures are covered in a clear and concise fashion. The basics of building a model are the same regardless if the kit is an OOP or new release.
What it boils down to is someone to build, photograph and write the article. Then hopefully there is sufficient amount of space in the magazine to accommodate it, whether it is a three page or twenty page spread. In How-To articles, editing them down to conform to allocated space, they lose critical amounts of information.
So what's the option...do a teaser in the magazine and publish it in the series of How-To booklets they offer.
I'm doing a series of articles, which I've put in my newsletters and blog...someone suggested I do the whole thing as a course making the chapters available on my website as a downloadabe PDF.