Well, when it comes to building your own pedals, the most expensive parts are the case,
pots, and sockets.
So the way I look at it is like this...
want to spend hours and hours over days and weeks tracing down the problem, solving it
eventually, and then realising that it isn't that good anyway?
Or would you
like to cut your losses, use that Frontline pedal as a case donor, and build something
yourself that could sound a lot better for peanuts?
If it's the latter, there
are lots of great resources online. But if you want a great pointer to some classic pedals
you can build for a couple of quids worth of parts on strip board, Guitar FX Layouts
around 500 FX pedals worked out, the vast majority verified by 3rd parties, all ready for
you to build.
Largely, but not entirely, dysfunctional.