On the pictures of the SAS Amatola the pennant number '4' is open, not closed. And, the ship has water-pump jet propulsion! No propellers in other words!
It has both;
it was discussed here before...
As for the number, I didn't change anything on the original drawing upper hull except for the 76mm gun and a couple of pixels right above the water-line.
there is some wierd pixel haze along the propellors
Oops, I haven't noticed that
Fixed and re-uploaded (might need a refresh)