Hello Traddles,
This was a nice quest; I thank you for it.
The "Coromuel" and the Clyde puffer "Sealight" .
See if you can find them Hint, hint, you need to use the mission editor.
I had seen the "Coromuel" before, she is allways visible on the map !
I found the Clyde puffer "Sealight". do East from the position of the "Coromuel"
behind the last row of buildings in the scenery.
As Traddles said you must need the editor because of the deep inland position.
BUT, I found a 3rd object in the surch for the Clyde puffer .
It is do south from the Clyde puffer 's position: in a desert land area in Brooklin
there is a ships drydock ! See the photo !
vr. gr. kind regards, Erik
Edit: 2nd photo and typo