Re Christian Oerter's signatures, we need to look at each one carefully, and they vary. The Oerter found recently in Germany, his rifle for Hankinson and the rifle in Windsor Castle use a few stamps - I and P, and possibly C. The I is then used to make T, H, N and so on, and a return added to the P makes R. The C, if a stamp, then makes a G.
Trying to carefully copy signatures with both uniform stamps plus the engraving is quite a challenge! Bob