Photo's can be uploaded to this site at
http://boonedocks.net/talkboard/talkboa ... oup=dspics
Make sure they are not hi res graphics or they will be too large to upload. From what you describe however, with a visible slot on the topside, you have a small d daysailer, not a 'Daysailer'. The Daysailers are 16' 9" long, and not kit built. What you are discribing is a daysailer variety of boat. There are several manufacturers of this variety. They are characterized as trailerable, under 20 feet, with some type of storage like a cuddy, and typically bigger than a dinghy.
It may be a Javelin which I think is a bit smaller than a Daysailer. The Daysailers are a class boat, which are built within class rules for the hull and rigging. They are identified as DS 1, 2 3 and I understand that they are now manufacturing 4's. The 1 & 2 have the same hull design, but the 2's have more of an aft bulkhead on the cuddy cabin, and enclosed seats, the 1's have wooden seats (and combings) and a longer deck on the stern. The 3's have an even smaller opening to the cuddy, and the hull shape is a bit higher at the back. They are not built within the class rules.
From your discription so for, except for the slot on top, I would say you have a DS 1, but more than likely, my guess is that if it is kit built, it is a daysailer type of boat.
We are all waiting with baited breath to solve your mystery, so look forward to the pictures.