I own a 1975 Roth 3/4 that belonged to a high school band. It was severly mistreated. About 10-15% of the varnish has flaked off exposing the yellow/orange wood beneath (see attached photos). I've yet to see an uglier bass it the 15 years I've been playing. The lower side panels, fingerboard, and tail piece were replaced about 5 years ago, but this is still a great sounding instrument. I paid about $900 for it, so I'm not too concerned about killing the value due to loss of original finish. How would I go about refinishing this beast without breaking the bank? I'm pretty handy with tools, so I'm not afraid to tackle this daunting project. 
