This is an age-old problem in the restoration process of an old tractor. There are some on e-bay and other tractor groups who have pre-made decals for sale. Most I see are for the SS/ST series of tractors.

What many have done is go to a local sign shop and have the decals made up there. No, it's not cheap. Some have reduced or even recouped their cost by getting a batch made up and selling the extras, hence the SS/ST decals mentioned above.

Another concern is what the original decals looked like. I'm not sure if you have any reference photos of your decals, but the sign shop will need something to make them from. If you don't have the photos, then you will have to post requests for photos on some tractor sites and hope someone has good pictures you can use.