This thread has me banging my head in frustration for you man. So out of curiosity I took my 1914 Eddystone bolt and put it in my 1917 Eddystone gun. The bolt would not even close.
Are you positive it was a 1914 bolt. For me it would go all the way in but once I tried to turn the bolt down it would not budge. Just trying to help trouble shoot. Good luck.