How much "tilt" do you require? Would a collimating ring work - M48 F&F? There are several versions available. Possibly you could convert one if not sufficient angle achieved and alter stock springs/fasteners. Dependant on how much room you have in the box for the outer diameter. Some collimation rings are much "narrower"than the one depicted here.
https://agenaastro.com/artesky-colli...s-art8022.html