On 27 July 2007, J Bray, Bedfordshire, United Kingdom wrote:
"I came across these adjustable rear shock absorbers left over from my racing days. They have 26 different positions which can be selected while they are on the car."
 

MGA adjustable rear shock absorber. These units are exceedingly rare, and no, I don't know where to find any. This is not the only type of adjustable shock absorber which was available for the MGA. I have seen adjustable valves which fit in the normal valve position in a standard Armstrong shock absorber.