The Monbulk Creek trestle bridge is a popular viewing spot on "Puffing Billy", a 15 mile long 2'6" gauge tourist railway on the outskirts of Melbourne, Australia.    This 37"x15" micro-layout is designed to demonstrate typical holiday traffic for this busy little line.  Construction is approaching completion, with the main scenic work now done.  Remaining pieces needing effort are the trains, track surface, trees, backscene, fine detailing and still more trees. The trains are d