Thanks for all the input. I did join all the angles with biscuits as well. I read about the scarfing but decided to just go with biscuits, even though scarfing might be the better option. Sorry I haven't updated in a while its been pouring rain here the last 2 weeks and I couldn't find a good day to use the TotalBoat penetrating epoxy sealer until 2 days ago. I have sealed in before I went to work for 3 days to let it cure with the nice weather, and have top deck paint to apply to the bottom and the inside when I go home the day after tomorrow. I also purchased all my aluminum to start welding up the frame. That will take the largest chunk of time for me in these early phases I'm sure. I was able to get a close look at a Fourwheel camper the other day in the parking lot of my local grocery store and the owner was kind enough to let me get real close. I'm wondering if the trim they use around the roof edge is proprietary or just a common RV trim. Its the trim that is about 3 inches and covers the actual gap in the pop-up when its closed. Not looking to rip off anything, but it seems like the way to make it work. I was also fortunate enough to have my father in law offer me up any parts off his early 70's SixPac camper that has been rotting on his property for the last 20 years. Originally I had passed on the offer but after pricing camper jacks, even used, I asked if it had jacks and it did. I removed them and they are old Rieco Titan hydraulics, that actually still work perfectly fine, they just need some wire wheeling and paint. He also had a collapsing aluminum stair that mounts on the edge of the camper door as well, good find! Ill update when I start working on the aluminum!
Thanks again!