Marcos Maniacs

Hi everyone,
It's time for new shock absorbers (as at least one has completely 
leaked out).  I have the original adjustable Spax at this time but 
have had little luck finding replacements. The Koni catalogs back to 
the 1960's do not list the Marcos so......any ideas?  I would rather 
keep the car as original as possible so Spax is still my first choice.
The numbers on the shock are 358 EH 308 (front) and 359 EH 325 (rear).
Any help would be appreciated.
Hampton Peterson
3M5463