I'm not real sure what your expectations are for the final look are but there have been a number of good suggestions ranging from Tru-oil to wait and do a good job. I offer a word of caution on any finishes recommended, from the picture it looks like the body is Poplar, which Peavey used often for painted basses in the '80s. Poplar can be a challenging wood for a natural or oiled finish in that it can go yellow-green, dark black-green, and get uneven splotches of tone. Part of it is due to the open grain nature Poplar has.
I just finished a refurb on an '86 Foundation S with a Poplar body, was painted black. Spent a small but important amount of time testing finishes. I've seen a wiping varnish of boiled linseed oil, naphtha, and varnish look great on Ash and other hardwoods but looked terrible on my test pieces. Ended up with Danish oil coats followed by coats of a naphtha/varnish wipe. There's no way it could have been done quickly. I'll post a picture of my results.
I just finished a refurb on an '86 Foundation S with a Poplar body, was painted black. Spent a small but important amount of time testing finishes. I've seen a wiping varnish of boiled linseed oil, naphtha, and varnish look great on Ash and other hardwoods but looked terrible on my test pieces. Ended up with Danish oil coats followed by coats of a naphtha/varnish wipe. There's no way it could have been done quickly. I'll post a picture of my results.