After going to British car shows for over 25 years, I have never seen the Ace Mercury Wheel Disc on any British car. This despite the fact that they were a factory option for the MGA, the Midget and the MGB. This is verified under the options listings in the Original MGB and Original MGA books. I have the MGB version of the book and the caps are mentioned but not pictured. The Original MGA book does indeed show the Ace disks. There is a shot of a rather beat up one, missing its center cap, and a shot of a complete one mounted on the rear wheel of an ’A. The Ace was also offered on the Midget and there are several shots of a Mk. II Midget sporting them in the Original Sprite and Midget book, including the photo on the back cover. The MGA ones are 15” in diameter (also usable on Z Magnettes), the MGB 14” and the Midgets 13”.

You know how when you’re not looking for something, you find it? Such is the case with the Ace Mercury caps and me. I was given an offer that I couldn’t refuse on a full NOS set of the caps that came in the original BMC boxes and wrappers. The caps have been perfectly stored and are truly mint. The caps had never even been fitted on a car.

The look is truly dramatic on the car and I’m sure it’s not for everybody. I do like the idea of going to shows and having something that I’m sure most people have never seen.

I’ve been asking a lot of questions about these caps to a lot of people but I’ve have been amazed at how many MG buffs really have never heard of them. I guess one of the main reasons would be that most of the cars have been fitted with wire wheels from the beginning and the person choosing the disc wheels might have been on a budget at the time of purchase.

The numbers on the boxes are (2) AHH 7044 and (2) AHH 7045. This marking is written in black magic marker. Although the boxes and the BMC wrappers are all in great shape they don’t appear to be numbered in any other way. One thing to be aware of with the Ace disks is that they are handed—ones for the left side of the car and ones for the right. The punched out “scoops” are oriented so the top ones are scooping air inwards towards the brakes. Two of the caps have the “scoops” pointing in one direction and the other two in the other direction.