Here's the backstory on this one... there is another post floating around with some early details as well.
A lady from Utah posted saying she had a never used red Weber for sale and wanted some help dating it etc. With the help of a few others here it was determined that it was most likely a 1978 as it has a stamped vent but no year code just a patent #. Also has the newer wheels which apparently changed in 76-77 and the cook book attached to the handle is copyright 1977.
This grill belonged to her fathers "Lady Friend" who had a flood in her basement that ruined the box so she gave it away to help raise money for a Cancer Research fundraiser. Funny enough while assembling I noticed that the front leg socket on the kettle had a burr that made it almost impossible to install the leg correctly. I'm wondering if that is the reason it was stuffed down in a garage for so long!
Anyways, after contacting the seller and working out a deal here we are! I'm thrilled that the money went to a good cause as well - a win/win for all parties!
Edit> Here are a few shots of the cookbook. Note the Yellow hiding in back on the second pic: