What is a 1988 Chevy truck worth?

we had a 1988 chevrolet c1500 clean just needed a paint job ...be for some one hit my husband and toileted it out ... so can some one please let me know what it would be worth it was a one owner when i got it and it had low mileage not even 20000 on the motor the blue book don't go back that far it only go's to 1991 on kbb.com ... i need to know what would be a offer i should take from the inc. co. on it please let me know asap thank a lot for your help