These four photos are from Australian Y Type enthusiasts, collected by the late Alf Luckman.
They are to give you some idea of how to fit them should you want to.
You would need to remove the valves from the front suspension lever-arm damper to make the damper into just a well lubricated upper wishbone. Failure to remove it will give your almost solid front suspension. Cut off the bit with the springs on it, making the valve into a simple ‘plug’ and refit it once you have filled it with SAE 20 oil. The rear lever-arm one would need removing completely. Such a modification would need your insurance informing, who might insist upon an engineers report as this is quite a primary safety issue for them.
Telescopic dampers do improve the suspension but it is up to you if you think the expense and work are necessary.
No one sells kits to be able to fit these dampers, so you have to fabricate your own brackets and fixings.