If the original designer is well respected then you have one major selling point ---marketing to potential new members.
Generally, the average member sees "original intent" as "outdated". So, it is critical to focus on the values or strategies of the original course not the length. So, it is usually important to increase the length in conjunction with opening up the course.
Trees are often seen by the average member as something that toughens the course. So, suggesting that going back to the original means removing trees will be opposed by many. You need to TRY to focus them on the challenge , playability, and agronomic benefits of tree removal. Don't even engage in the argument as to whether the course will be "easier" or "harder" with fewer trees. Hopefull you can point to another respected course in your area that restored its course. If not, then you sell Oakmont and prepare for the Augusta counter argument . Dismiss Augusta as a course just for the pros while Oakmont is a great course for members.
Try to suggest that the course will be "better" because the original design challenges were intended for shots hit off line. The challenges at the green are enlivened by more width. You may be able to show that the original course had a "signature' feel that was homogenized by parallel trees running along the fairways.
It helps to have some archival things like photos or designs that show the original charm and if you can hire Joe Bausch to research the papers he could find articles that spoke highly of the course at its inception.