Over half-a-century ago, in my financially-challenged teens and never having seen a professionally-made bass, i made my own for about £12   I bought a couple of bits of unplaned mahogany (one for the body, one for the neck&head), a strip of ramin for fretboard, some fretwire, and the cheapest set of machine-heads and strings you could buy (at Bell's Instruments, Tolworth)   Couldn't afford a decent pickup, so i bought 4 alnico ¼" rod magnets and raided an old solenoid for