Thank you BobH and Pawel66 for your replies. I removed the doorcard to search for the key number on the door handle and the number on the door handle is the same as that shown on the data card. This does not, as mentioned by you, confirm that it is also the correct tumbler, but I will take a chance and order the key with this number.
Pawel, could I check the correct key profile from the tumbler?
You can check the profile on your current tumbler by looking at the key profile that fits your key hole. They are shown on attachment 1. The black cross sections on the drawing is the image of the key hole (not the key!).
Then you can look at the key code from your data card and figure out profile from attachment 2.
Then you know what you have and you know what you should have as per data card.
If you do not have the profile from the data card and you would like to have one, you have to find the tumbler with the profile you need. Maybe the locksmith will have it or you need to fight for it on ebay - difficult because people who sell used door handles or tumblers have no idea what you are talking about, so the only hope is that they can send you picture of the key for you to figure out profile. The late Pagodas, with master key, had just one profile. I have no idea if earlier Pagodas had more profiles.
It is easy to cut key to tumbler or tumbler to key, but no one was able to change the tumbler profile for me.
I went through this re-creating key sets for 190SL and Ponton - a true nightmare. The only one I did not find was the ignition key as I could not find original ignition switch for 190SL (the early one, with starter activated by key, not by button).