servo
If it has a white servo horn and the plug looks like a Deans It is the old Goldberg retrack servo they made for their retracks. It goes 90 degrees both ways. It was bulit in a D&R servo case and gears. Ace had some servos made by them and R&S Systems also used them, I still have an old R&S Radio From 74 or 75. I still have one of the GB retrack servos