what happened to the original charlie from willy wonka
He became a veterinarian.
Peter Ostrum
Ostrum worked in Lowville, New York both as a veterinarian with the Countryside Veterinary Clinic (working mainly with horses and cows), 
wiki:20186723
Peter Ostrum [SEP] Veterinary career
, Ostrum worked in Lowville, New York both as a veterinarian with the Countryside Veterinary Clinic (working mainly with horses and cows), and a managing partner with Dairy Health & Management Services. Ostrum also took part in "Veterinarians on Call", a Pfizer-funded video series that highlighted the work of large animal veterinarians.