Thats a good job youve done so far but i wouldnt bolt a prop on the front of that thin a shaft,sticking out that far.Are you planning on using the washer agaisnt the shaft and then the second washer against the prop?That is going to wobble and then fail in my opinion.You need to take off the square drive and then put a proper hub on.After you take the drive shaft off post here as to what threads they are and one of us or me can point you in the right direction for a proper hub.I even make my own and purchase somtimes also.I have some made up right now.Im not critisizing you at all,as i said your doing an excellent job, i just want to be sure you or someone standing around you doesnt get hurt.Ive posted a couple pics of how mine look so you can copy them.