Yes, TSC has old N-style arms in stock in most places. I even have a spare in my barn because when I needed one, I bought two because I thought I'd eventually need them.
These might not be the right size and could cause some geometry problems. I'd check with a New Holland dealer to get an idea of cost of new before trying TSC. That way you can get the correct ones. Also, do you have the lift arm connecting forks from the rockshaft to the lower arms? Those will probably end up being more expensive than the lift arms, especially if one is the adjustable length type.
...and don't forget stabilizers and stay chains...and more.
Here is a picture of my old Ford Jubilee with the standard
3PH parts. You won't have to have the drawbar or stays, but the basic
3PH parts are there. Notice that the right lift arm has a barcode on it near the tractor. That's the new lift arm from TSC.