Well there are just over three months till the Region 1 release, so there's plenty of time for the Making Of documentary to be included as a DVD extra. More impressed when a lengthy Making Of documentary is included as an extra on a DVD/Blu-ray release of a film.
Apologies Richard if I've mis-read what you posted inbetween the two pieces of movie poster artwork for End of the Road, but this isn't going to be a Warner Archive title (based on it being available for pre-order on Amazon.com and a recent post on the Warner Archive's Facebook page from this...
Have done a HTF thread search, and there don't appear to be any existing threads for the 1970 film End of the Road, starring Stacy Keach. It's being released on Region 1 by Warner Home Video on Tuesday 18th September (source: Amazon.com).