Hi Jack.
You are not alone, I am also trying to find out which damper to use for my 1970 4/4 which has developed the dreaded wheel wobble. I have tried everything I can think of including rebuilding the suspension new dampers blades even new wheels but to no avail. I have heard talk that VW polo steering dampers might fit, I looked at motorbike ones but they were all about half inch to short, if I get stuck I think Mulberry fabrications have developed a kit so I will resort to paying a bit more in the knowledge that it will fit and should just bolt on. If you do in the mean time find out which fits I would love to hear about it.
Steve