I have a Gillette 3 piece "old type" dating from around 1910-1911, it has a 3 hole baseplate that has an open comb/teeth and the top cape has a threaded post and two other solid post one on each side of the threaded center post. My question is, do I have make a shim from another blade before putting another blade in? Can they use modern DE blades? How do they shave? Thanks.