Not an easy call, but as Vombil says it will be hard to find a buyer over $10k. If it is a 4.2L I can't see it being worth $35-$40k unless the restoration is near concours, probably closer to $30k.

Not a good way to be selling it unfortunately, normally the better return would be how it was before you started or when it is finished. You never know though, only takes one buyer and if someone who wants it knows these cars well enough they may see the value in it however the general mass of buyers probably won't.