A replacement axle will be many hundreds of dollars, are usually manufactured to specific dimensions, and generally are not returnable so I wouldn't count on a random set of dimensions you get from the World Wide Web. (However friendly and helpful people are on this forum.)
You'll need to decide what kind of axle you want:
- Torsion
- Leafspring/Shock
Then you'll need to contact a welding company and have them decide how to go about raising your camper to a height that's desirable for you.
Then you'll need to contact the axle manufacturer and find out what they need for dimensions.
I got my replacement torsion axle from Canadian Axle, the makers of the FlexiRide adjustable torsion axle.
They were able to make one to my specific dimensions (for a 13'
Scamp, so that doesn't help you) with electric
brakes and shipped it to Massachusetts for US$600 (axle,
brakes and shipping for US$600) which seems like a great price given the long wait times from
Scamp and other manufacturers.
So, I think, after you make a choice of axle type and raising method, you should get some actual dimensions off of your trailer and then get an axle so you can get to CAMPING!!!