As you can see the main wharf is clad with stone, while the other one (an earthen section) has wooden pilings shoring it up. This kind of earthen wharf was more common than you might think, but could be completely removed if inappropriate.
One end of the stone wharf is rather worse for wear, and the other side of it has two barred openings where sewers or streams could exit into the harbour.
There's two smaller sections for the wharf to connect to the main board. An earthen ramp and some steps (large enough to take a standard 28mm figure's base). Two 6" jetties finish off the construction, with wooden pilings to match the earthen wharf's.
I think you'll appreciate how well the whole thing fits together. Mr. Fitzpatrick is amenable to taking up your cause for a wargaming project - email him and I'm confident he'll be able to solve your design and construction quandary!
Here's two final shots of the wharf in action!