Coping With The Coaming

Plastic sheeting separates the laminations from the deck

The coaming is assembled from layers of plywood, laminated together. Reading the manual and picturing the assembly I could see this was going to be one of the more challenging tasks in building these boats. I again referred to Laszlo's wood duck blog, and the technique he illustrated for assembling and installing a laminated cockpit rim seemed much easier.
Laszlo recommends putting plastic sheeting on the deck around the cockpit opening and using the boat as a jig to glue up the pieces of the coaming. The pieces will form to the proper shape to mate to the deck, but the plastic stops them from adhering to the boat. Once the epoxy cures, the whole coaming assembly can be removed, allowing easy access to all sides for sanding and shaping.  Once all the rough (very rough) edges have been smoothed the coaming can be epoxied in place on the deck. When I used this method I only had to be concerned with cleaning up the squeezed out epoxy from one glue joint, not several.

The inside rim of the cockpit rim is easily sanded

Once shaped the rim is epoxied to the deck

Very little squeezed out epoxy to deal with using this method

Help Is A Mouse-Click Away

So, you're building a boat in your basement? There's a "Support Group" for that. I've done my share of internet forum surfing, forums are great sources of information. The CLC  Builder's Forum is an exceptional resource for boatbuilding. I've spent many hours going through the forum topics, reading several thousand posts on all topics.
The "experts" are knowledgeable, encouraging, courteous, and extremely helpful. This forum is a treasure trove of terrific information freely shared in a friendly environment.

Most common piece of advice on the CLC forum - You can't have too many clamps.

One good thing about building two boats at the same time, is being able to try different approaches to the same task to get better results. When I glued the sheer clamps to the hull side panels on the Chesapeake 16lt I wasn't as careful with the excess glue as I should have been, the panels ended up being a little stuck together and were difficult to separate. When gluing the 17lt I was much more careful and the panels came apart easily.

The sheer clamps are long strips of 3/4" stock glued to the tops of the side panels, the deck will attach to these.