I got phone call from Jim Garn – Kinetics.
They send a couples of 551 piston to DH-B in UK for repair. After investigation DHB claimed it is not repairable and charge some repair costs.
Now Kinetics wants a new 551 piston units (should be available in A/X under model code CPS3500 – to be verified). They are waiting price.
If you need any help with the model code, please feel free to contact me. I don’t have access to the TP for now, but I hope it will be solved by next week,