Bit of a long shot but thought I'd give it a go...
80W 12" speaker, model CK80 - intended as a keyboard amp but obviously works very well with bass. 3 inputs, very useful for using for small gigs with other players - used it very successfully with bass, mandolin and vocals. Reverb with separate controls for each channel. Also has extension speaker output and reverb footswitch jack. Full working order but some controls a bit crackly on occasion - will give it a spray with the switch cleaner if I get a chance.
[b]£50[/b] pick from Salisbury, or can meet up anywhere along the M3 or A34.