+1 for ACF 50.
Used it on bikes for years.
BIG plus, as far as Morgans are concerned, is that it is intended for use on aluminum bodies particularly to stop galvanic corrosion where aluminium joins steel.
If I had a new Morgan I'd spray all the underside, engine block, in fact everywhere that isn't paint or leather before using it on the road!
On my 4 year old Roadster the area under the spare wheel looks a prime candidate. Also the engine and that general area, the block is already suffering from surface corrosion, not a problem but looks scruffy.
