This is real, and it is a period correct accessory for MGA, but it is rare, as there was only one ever made. This item was sold on eBay with the auction closing at 5:26 PM on Dec 31, 2020 for $86.55. In my humble opinion, someone got a real good deal.

Here is the story behind it (according to the auction listing):
“Doc” Watson was a friend of mine. I first met him at the Indianapolis Speedway years ago when he and Linda Vaughn were promoting the Hurst Corporation with sponsored Indy race cars. He was from Michigan so I also saw him at various events in this area. He owned a motor sports accessory and collectables store in Grand Blanc Michigan for a while that Linda managed for him that I enjoyed visiting.

Being a sports car enthusiast and driving MG’s for years I always kidded him about the fact that he never made a shifter for an MG. One day while I was in my shop in Swartz Creek he showed up with a box in his hand. He gave it to me and said, “I don’t want to hear any more s—t about a shifter for an MG.” -- The seller's trading name was "sebawing".