This letter fold has two parts. Part One is the letter fold itself. Part Two is my variation of Edwin Young's Broken-Mended Heart.
Here is Part One.
This model is quite easy in both its concept and the folding required.
We start by folding the paper in half lengthwise. We make diagonals starting from the center (you will need to make a marker crease here). Then we roll the model up from both sides. The remaining flaps are tucked into each side. The top flap has a little bit of extra fiddling so that it looks right and so that we get a tab to pull to start the letter unfolding. It's pretty secure until you do that.
You can slot anything you like in the front pocket. I choose the Young heart (with a few modifications to make it two sides and secure) because its construction allows it to be slotted over the edge of the pocket for effect. This will stay put provided you don't turn it upside down or knock it. Put the heart in the pocket for safe keeping while transporting the letter.
I have completed diagrams for this model and for my modified Young heart. I have also completed diagrammed instructions for the Double Wrap model. I will make them available just as soon as our crashing web page host machine is upgraded. That might be a month or two. I'll keep you posted.