A quick update: the Hagström has had CTS pots installed and the truss rod now works as intended. It also got a setup with new strings (these – they feel great) and plays better than ever. There is still a bit of a treble drop when the volume is turned down so I am considering doing a so-called treble bleed mod. The tone controls work great now!
I also got a new overdrive pedal, a Boss SD-1, for an embarrassingly small amount of money. Sounds very good although I have not played it at proper sound levels yet. As an experiment I have started using the stereo option on my chorus pedal and plugging into both channels on the amp – again, very pleasing sounds at home but the real test comes at band practice and more proper sound levels.