Hi Glen,
A very exciting milestone indeed for your build, congratulations. Not much I can add to what has already been said, lots of excellent advice here as one would expect. Having some helpers will make the job a lot easier and less stressful. For maneuvering the motor & hoist, practice is a good idea. Sweep the floor so when you are trying to maneuver the hoist it will roll smoothly, maybe give the axles a bit of
oil or grease to reduce friction.
Take your time and if you run into a road block, stop and consider your options. When you fit the bonnet (hood), use some putty or modeling clay to check for clearance between the air cleaner and the underside of the bonnet as you slowly close it. The amount of clearance will be evident in the thickness of the modeling clay.
Be sure to put the clutch disc in right way round …
… have a glass of that fine South Australian red wine, AFTER the motor is in and be sure to have Alfie supervise.