Hi quiltingbee12-
I don't think you will find the pattern; I tried double clicking on Peter Stringham's name at the top of the link you provided and nothing came up. You might try contacting rising star quillters - I am sure that they must have contact info. However, I would encourage you to just wing it.
Marcia Hohn has a fabulous site [QuiltersCache] with tons of free quilt block patterns. Monkey's Wrench is very similar to Snail's Trail and has a clearer 4Patch center. Go to her site and pull up the Monkey's Wrench pattern.
That will give you most of your block. Then you can just add the trapezoids [or half hexagons] around your block. and then add the green background pieces. If you are uncertain of the size, copy the block that ManiacQuilter2 has very helpfully drawn for you, make it the size you want on your computer, then print out and cut out the pieces as templates.
Best of luck and thanks for the link, I will make it too. - Judy