Grohe is a good German brand, I don’t know if they kept with it but years ago they were reaching out to the repair industry and trying to build a system for parts to be available for repairs, something that Kohler thought was beneath them. Kohler snubbed the repair industry and so their high-end consumers suffered for it.
My house was built in 1972.
My shower stall valves are the old style. NOT a mixing valve which became code sometime AFTER 1972.
When I moved in 13 years ago I replace the handles. Went right down to the local Home Depot and bought new Chrome handles to replace the original ugly plastic handles.
A few years ago I had to replace the valve. Again back to the local HD and bought a replacement valve. The funny thing is I realized that the previous home owner had bought the wrong valve for the right side handle. Meaning it turned counter clockwise to open it up. Whereas the right hand(cold) valve should turn clockwise to open up.
I am sure it was the previous homeowner that did this because there were multiple things he did that were absolutely wrong when it came to repairs around the house.
Costco was/is selling a Kohler “LIR” kitchen sink faucet that is supposed to have a lifetime warranty. About $179.00. If you run across one of these, run away as fast as possible. The flow rate is miserably slow. If anyone knows how this POS can be fixed, please let me know.