An acoustic guitar with a dodgy, onboard preamp that had to be replaced.
What should have been a straightforward job became a little more complicated becauset the original preamp had a particularly large footprint. It was an older, discontinued model and the manufacturer was unable to supply a replacement that was as large. As it turned out, it was pretty difficult to find any manufacturer that had a unit that would cover the existing hole (and patching and recutting wasn't favoured for cost reasons).
After quite a bit of internet rooting, a unit was found that would cover the hole in the guitar's side. Great.
Just one problem though… Although the bezel covered the hole, the mounting screws were located such that the front two had nothing to screw into (see the locations marked on the blue masking tape).