Re: Greetings from Ireland
Welcome to the forum. We're glad you've joined us. I hope we can help you with any problems you might have.
You said you've "lost the half moon washer type thing". That is critical. It's called a 'Woodruff Key' and must be there to keep the small gear from spinning on the shaft. If it is broke or missing you'll have to replace it. It is a metric width and length.
Other members will have more advice for you so keep watching for more replies.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"