This is probably what you need:
https://www.bighealey.co.uk/jaguar/axle-5?page=2
They make the 19 spline axles for their race cars.
I do not know what engine you have, but if you have to have new axles made, you might want to think about going to a 30 spline and save yourself a lot of grief later. I upgraded mine over the winter last year. You can do it 2 ways. 1) replace the carrier, or 2) you can replace the internals of the carrier with 30 spline gears and use the 30 spline axles. Either way, it will be a lot stronger.
If you are in a real hurry, I have a set sitting here from a 65 Jag that had tapered bearings if that is the style you have.