1. No one has ever demonstrated that 1917 matte proof cents were made. The order to end all proof coins came in October 1916. There would have been no purpose to making proofs in 1917 and there was no master die or hub change that year. (PS: I've examined 1917 quarters that have spectacular detail, but they are documented from the source, T. Louis Comparette, as early coins off new dies -- part of the normal range of coinage.)
2. As with 1917 proof claims, this has never been demonstrated. Entirely new master dies and hubs were made for latter 1909, following removal of the initials. The new reverse had different relief than the original with initials. No dies with initials were retained for any purpose. (Grinding VDB off the rev hub was considered but rejected as being an incomplete solution.)
3. Matte proof dies for Lincoln and Buffalo proofs were made by sandblasting normal, new working dies. These were used in a high-pressure medal press to make the matte proof coins. Excess pressure limited die life and sharpness, and some condemned proof dies might have been used in normal toggle presses - but we have no records one way or another. Additionally, no scientific examination has ever been made. (There is ALWAYS a range of detail in coins made under "identical" circumstances due to die wear, planchet hardness, and mechanical inconsistencies -- enough to confuse ordinary visual clues.)