I agree with the two posts above
I know that axle stand manufacturers say not to use 4 because of health and safety but I know many people who use 4 axle stands regularly and as far as i know as long as you are methodical and make sensible precautions then it is fine
The only things to make sure of are;
All the same height or adjusted to the point where the car is level
flat smooth surface for the trolley jack to slide and adjust as its raising
The rear of the Morgan chassis crossmember is flat of course where you put the axle stands so I would suggest a wood block on the top which will bite into the 'U' of the top of the stand stand and provide a flat surface
This just stops any risk of slippage
