Case sold the Outdoor Power Equipment division to Ingersoll in late 1983. Ingersoll continued to make these tractors with the CASE brand on them as part of the agreement. Slowly the Ingersoll name was introduced on the tractors and as the Ingersoll name became more dominant, the Case name began to slowly disappear until it was gone totally sometime in 1987. So, your tractor is known as a "dual-badged" model and I agree with gator that it is a 1985 model.
Congratulations on your purchase.
When asking questions about your tractor, it is helpful to state the model (446) and the PIN/serial number because the 446 began in 1972 and ended in 1988. During that time, a lot of changes were made to how they were built. :thumbsup: :thumbsup: