Gray
That’s a GMC 630 see the the small pick up Cab the 700- 850 has a bigger and wider cab. No one makes a cracker box Mark Savage did back in the 80s I know one person who has one and he won’t sell it I’ve tried. I have a couple resin GMC cannonballs but don’t want to sell them there very rare. Rick Manz made several 1/48 resin trucks in the late 80s. I think Herb Dekes has some of his trucks look him up maybe he can help. I hope you have deep pockets to deal with herb.