You went the wrong way about getting the blade boss off, they come off easier than a victa one, simply use emery paper to thoroughly clean the crankshaft above the blade boss until its shiny, oil it , use a suitable sized socket and a rubber mallet (I use a hammer on a socket but I keep cheap tools for these purposes) to mang it up the shaft, clean where the boss was with emery paper and it will slide right off.
