Frank, glad to here that you at the "back together stage"!!!
My machine is on carpet ,so, I waited until the head was on
before I leveled.
If you plan to get it back to four legs , I would do that
before I got into any serious leveling.
I like my game a bit slower so I did not go a perfect level
on the box. Of course left to right is CRITICAL!!!
If you do not have any mechanical help to lift, move, the head
in place, you should get some strong friends to help!!!