Revell bringing out 1/144 scale tug kit in July , cost about £13. Looks quite good
for a layout incorporating a harbour scene.

Have you got a link to that as I can only find a 1:108 version ?
I might be interested in the smaller offering.

It's on Osborns site as a forthcoming item, also Wonderland Models of Edinburgh.
Can't add link, too thick.

Here you go:  http://www.osbornsmodels.com/revell-05213---1144-harbour-tug-boat-fairplay-iiiixiv-30151-p.asp