Custom Admin Panel vs. WP et al CMS

been developing websites since 1998 with help from a lazy mans tool (dreamweaver) and html/css/javascript
managed to avoid all CMS so far, except CushyCMS, which i have used to give clients easy access to update html page content
all my clients are small businesses in a developing nation so… small budgets and no need for enterprise level solutions
now getting into responsive web design… fun fun fun (sarcastic tone)!


An important client is ready to contract a responsive re-design, woohoo!
i have everything ready to go except one single aspect
they are asking for Wordpress and i am once again wondering if WP is the way to go
the sole reason they want WP is to edit text/images and ADD NEW PAGES without my intervention
the pages are going to be custom designed responsive templates in html/css
WP is overkill and i prefer the idea of a custom php/mysql admin panel
basically letting the client add and then edit pages when they want to
or something along the lines of a miniCMS or a CMSlite
CushyCMS was a great solution for a few years but now i need to go one step beyond!
just one step though, no more.

Any tips and advice much appreciated.