You may be able to discover it.
If you can fabricate something like a straight rod coming from the arm attachment bolt you may be able to slide the LNB along your new rod until you get a signal.
Then fabricate a method to attach the LNB to the rod.
Or try a Channel Master search. They are a big company and make many products.You have a part number.
You will also need a direction to the satellite you want to address from your longitude & latitude
Good luck,
Joe