If it's still stuck, it may be your pivot bolts at the back of the cab have rusted. They should still pivot, but it may be sticking here.Check your throttle lever, mine would get caught occasionally.
On some of the older ones there's a electrical connector behind the seat that needs to be disconnected before lifting the cab.If it's still stuck, it may be your pivot bolts at the back of the cab have rusted. They should still pivot, but it may be sticking here.