Hey Recurve60....First, WELCOME to TinBoats! You've come to the right place to find all your answers and make great friend/family.
Your mod looks pretty nice so far. It certainly will be heavy duty! I can't tell from the pictures, but that looks like it might be pressure treated wood. If it is, that will cause a few problems down the road with pitting into your aluminum. Use the search feature in the upper right hand part of this page and read about pressure treated wood problems with aluminum. We've all seen this conversation many times.
Other than that....if you have any questions.....please don't hesitate to ask.