Bennett 766 are cool pumps.

On the side panel is a small access door. Open that door and if you look inside half way up in the middle of each door (front panel as you refer to it) you will note a steel rod that latches the door in place. Turn/dial the release rod to unlatch the door. Once released the door will swing open. Do the same for both doors.

Bennett 766's are easy pumps to restore as original and reproduction parts are readily available.

I sent you a PM.

Dave GILL,
Dave's Garage & Memorabilia, Inc.