Mercedes - Benz R129 SL Models - Seal & 'O' Ring Repair Kit for Hydraulic Front Locking Cylinders - to Fit OEM / M/B Part No 129 800 1672.
 
This is a Repair kit consisting of 2 x 'O' Rings & 2 x 'U Cup' Seals, to replace defective / leaking seals on the Top Latching Hydraulic Cylinders (Note for both Left Hand & Right Hand Sides), which secure the Hard Top Front Lead Edge above the Windscreen / Frame Pillar

 The 'Cup' seals & 'O' Rings are made from very high quality / long lasting materials :

1 - 'Cup' Seals x 2 : Manufactured from Polyurethane (PU) Material, with a Specification of:
   - 'Shore Hardness' Rating of 70 - 90 &
   - 'Standard Compound Working Temperature' range  of - 40'C to + 80'C

2 - 'O' Ring Seals x 2  : Manufactured from Nitrile (NBR) Material, with a Specification of :
  - 'Shore Hardness' Rating of 40-90 
  - 'Standard Compound Working Temperature' range of  - 40'C to + 110'C

3 - Similar Repair Kits for other individual Hydraulic Cylinders used on the Hard / Soft Top Mechanism of the Mercedes R129 / SL Models, can be sourced & supplied on request - please msg. me with your requirements & for a price quotation, plus confirmation of  Delivery Lead Times (which may vary / be extended, dependent on individual requirements) 

NOTE:
A - There are several informative /  helpful articles on YouTube & various Mercedes - Benz Owners Club Sites & Forums, showing how to fit these items, which should be well within the capabilities of a good / competent DIY Engineer / Merc. Enthusiast...!;
However....
B- If in doubt of your Engineering skills & Capabilities.......please consult, or employ a suitable competent Mechanic to fit / complete  work.....!