My very unglamourus attempt at Peters shock mod. I went with 80lb shocks from Mcmaster-Carr 9416K17 and inserted them into the original housings . (Safely getting the original apart was quite a treat/dangerous, knowing there was still pressure inside)
I reused the original top mount with thread bushing m10- m6-1.0. . Happened to have a couple of furniture leg protectors that workg greatin centering the bottom in the original tube. 2 rings cut off the smaller softer protector and used as a shim so larger one fit tight inside the larger and 1 as a compressed sealing ring at the top, also flattened the bottom of the larger one to set it a little deeper ) I used all the old washers and clips to hold it all together ( bored out to 18.5mm) , using the press with a couple sockets to compress the sealing washer.
Happy with the results , may need bump up to 90lb/100lb shocks but the change out will be easy, but no spoiler flat deck it should be enough.