Some Morgans are prone to the propshaft rubbing the prop shaft tunnel at the axle end. Although it may not have done it before, it is just possible that it had been running with a very small clearance. When the axle was disturbed by having the car up on a ramp and lubrication of leaf springs, it may have settled in a slightly lower position, enough to cause contact.
If other simple checks on wheels, brake drum tightness etc fail, it may be worth checking this out. Remove parcel shelf and look for witness marks where the shaft enters the tunnel.
