Stevens tip-up 38-35

[Kurt]

That is a interesting caliber that got my interest and did some reading on it. Randy the .375 Win is about as close to a parent case that is out there. The base could be swaged down to the .403 pretty easy with a simple die and if the rim needs to be turned down to fit the rim recess .492. Pacific tool has a .38-35 reamer to make a die from a die blank.
A sizing die can be made as well as a base swage die by not running the reamer in full length.
Something like this can be done using a good drill press or mill would be a couple steps up with a vice and careful indicating the die blank in a set of V blocks if a lathe is not available. I have used a drill press doing this before I got the lathe.
No I wouldn't chamber a barrel doing this