Maybe six months ago my roommate was cleaning out his garage and and decided to throw out a karcher power washer. Although I already had two power washers...I took it home, cleaned it, rebuild the carb, slimed the tires and it ran like a top. After 3 or 4 uses the pump wouldn't turn on without throwing the choke/dropping the RPMS. I figured it had a few good uses left in it before the pump died, and the Honda 160 side-post engine was still worth quite a bit (for go-karts or what-have-you.) That's when my girlfriend and I, on our daily combing of Facebook-Marketplace noticed an add that simply stated "it still works" for $100 After some back-and-fourth I ended up trading the power washer plus a twenty dollar bill for the "it still works" but I've since been banging my head against a wall. There is a special place in my heart for any old/quality well built tool, and I had never got my hands on one of these...merely watched with glow every time I've been to the locksmith to get a duplicate, and seen their variety of gizmos. It reminded my of my grandmothers Singer sewing machines, the quality steel, the old hard rubber power cord with the black switch, the faded and chipped black paint job revealing the years of use someone had spent duplicating keys. We took it home and started researching the model number and finding out what we could. We had traded for a Mini-Mite 008-50-44. After cleaning /lubricating and re-tapping a reverse thread bolt, we noticed the belt was incorrect(the PO actually informed us but it was obvious), and ordered a new one along with the only two brass bushings holding the shaft in place. I was so excited to test it out that we went to my local locksmith to purchase a few blanks. They informed us that it was policy to not sell blanks. (I didn't understand why, until i noticed a key from them i had purchased previously had their logo/name engraved on it.) Naturally the next step was to go to Home Depot and pay the full $2 to get a key made, but then just take the blank...
We got home, plugged the machine up, turned it on, aligned the key and duplicate and started cutting. It worked, but the blade was wobbling all over the place. You could make a cut one direction...and then erase it going back the other direction! That couldn't be right! we ordered the new belt and bushings hoping that their installation would correct this, and allow the shaft to stay in place, however that was not the case.
I will include a link to the original manual, as well as a you tube video I took upon writing this, in the hopes that one of you geniuses could tell me exactly where the "user-error" is and how I might go about fixing it

TLRD: Have Mini-Mite 008-50-44
http://mfsales.com/ilco/il-old-machines.pdf
The whole shaft wobbles/makes sloppy cuts
https://youtu.be/pHPpUUZlyLU
What is wrong?
PS: i noticed the key wasn't fully locked in place, however it merely threw it in there to show how the whole thing slides left and right which is most noticeable at 26<