:welcome: to the Starmada!
Good move from the lost sea of rotten glassers, I normally scan the resto forum but I missed your Chief thread somehow.
Yeah that front motor mount should have a 1.5" piece of ply that rests on top of the ribs that are fore and aft (rests on 3 ribs) and is attached to the cross piece the mount is bolted to so the weight is spread out more. I can't tell if the mount has that piece underneath.
Something else I can't see is the "horse collar" that goes around the keyhole where the motor mounts to the transom. It may be there but if not that's going to be a problem as the transom needs it to be the correct thickness.
Some suggestions for your motor.
I can see the exhaust and intake manifold is on the motor, it's one piece.
I would pull the spark plugs and check them for any signs of water. With the plugs out I would turn the motor over to make sure it moves freely and then oil fog the cylinders and turn it over some more before putting the plugs back in.
Check the motor oil and look for any sign of water intrusion.
Inspect and replace the ignition parts if they look bad. (Points, condenser, cap and rotor)
Make sure the water drain plugs are in place and tight on the block and manifold.
If you're going to add fuel and a battery then put a garden hose in the water inlet where the outdrive mates up. Looking at it, to the left of the large hole is a smaller one that is the water inlet.