If you used a compass & made a 114MM dia circle on a piece of thin stiff clear plexiglass then made a mark at any point in the circumference (mark #1) then made mark #2 67MM away in a straight line tangent & so on (3 more) & now you have 5 equally spaced marks on a 5X114MM circular pattern (check that each mark around the circumference is 67MM away from the next mark in a straight line). Drill a mini hole thru each of the 5 marks with your smallest drill bit. When the template is properly located you'll set the plate on the hub & drill into the drum at 5 places just enough to live a witness mark so you can remove the plate and drill it to size & yes as said use threaded studs. Easy so far. Now the prob is going to be locating the plate concentric & I'm not a draftsman. Either make 4 marks on a smaller 100MM circle and drill them out to the exact (miked) OE stud dia then cut the center register out (dont have to be exact) & slide the close fitting template over the existing 100MM studs & it will locate your new 5X114MM holes exactly & use a mini bit on your drill press to make 5 witness marks thru the plate & on the drum then remove the plate & drill em to size or if there is a drafting method to find the exact center of the register and line up the center of the 5X114MM circle with that point then the new circle will be located concentric.