If this is a 48 I thought I could share a couple photos of the 47-48 front grille with a three bar front grille and broader grill surround (mustache) used during those years. Perhaps, GMC modified the grille design later at some point in 1948 to the 4 bar grille that is on your truck. But the 4 bars appeared in 49 for sure. The three bar grilles define the rugged GMC look. Always liked those.
I understand that originality isn’t a priority- but for others this may be interesting.
As the others suggest, do your homework and look it over. It’s exciting to find a truck you want / there is always always another and perhaps better deal to be found too - to keep it in perspective. First sightings can be wicked exciting, but now that you found something that interests you - expand your search along with this one.