I looked on the Ahead 4 Healey's web site and discovered that the shackles that I was thinking of replacing are about £50 for the set and that seemed awfully big.  I decided to find the second pair of shackles to see if they were salvageable. Below is the original frame in storage outside the back of my house.

When I look at the rear end I see that one of the petrol tank straps is still useable.

When I delve in I was please to discover that the chassis still had the shackles.

So I got two of my favourite tools out and removed it.  Great fun.

The chassis looks a little violated but what can one do?

I cleaned up the shackles and decided that the inner two were too warn so I ordered replacements for those two and saved the good two.  Better than a kick in the teeth I guess.