Your compression should easily exceed 200 psi. The bore cannot possibly be 53.47, as the bore new is 54.00, so your tools or technique are off.
This is real basic, but are you choking the motor for a cold start? First start can be a bitch for a rebuilt Leopard. To choke it, put the air box on and place your hand over the inlet tubes. You might have to slightly wedge open the throttle with a piece of thin (3mm) plastic or get somebody to manipulate the throttle. You actually can leave the key in cranking position and have one hand doing the choking and the other working the throttle. I’ve also resorted to spraying starting fluid in the inlet.
You haven’t clarified whether you were using the key start ignition before the rebuild, or if that also is new. The crank trigger magnet for a push-button Leopard is different than for a key start, so if you mixed them up you can get a very weak spark but no start.
At low speed cranking (like with a starter) the carb can dump too much gas into the air intake plenum, so you’ll get leakage of the excess gas out of the plenum, that you might interpret as gas not getting into the motor.