I finally tackled the time-consuming task of adding a wood deck on the float bridge today.
I don't know what took the most time, but cutting, staining and gluing all the individual planks took 6 hours non-stop. At least, it was quite relaxing and enjoyable, far beyond my expectation.
Before gluing the planks, I was required to glue a 0.5 mm thick styrene sheet over my original deck to get a flat top flush with the rail spikes.
Wood planks, made of balsa, were stained with a mix of India ink and alcohol. Color pictures of the 50s show that the bridge planking was relatively new and not totally greyish. Using alcohol was a safe bet to get that look.
The next step will be to further weather the planking according to prototype. Oil spills from locomotives were quite impressive!