Changing frozen OGZDL.L stocks against Moscow GAZP.ME stocks

Speaking of Gazprom, I have two questions for the specialists:

1. According to Yahoo Finances, the GAZP.ME stock has been trading on the Moscow Stock Exchange (.ME) for some time.
   
   
   
   
   According to my information, all derivatives on the OGZDL.L shares on the London Stock Exchange were frozen on March 1, 2022, shortly before the crash.
   
   
   
   
   
2. Do you know how this happened under what kind of conditions?
   
   
3. Do you know what exchange conditions the holders of OGZDL.L shares had against GAZP.ME shares quoted in rubles?
   (Rate 198 rubles = €2.01)
   or was this no longer possible for Western owners because there were already sanctions against Russia and all capital was frozen?
   
   
4. According to the German European company register, the well-equipped Austria subsidiary GAZPROM NEFT TRADING GmbH has now moved to a more upscale address on the 1st floor |
   GmbH but is completely invisible in many company registers here in Austria.
   Do you know more here?
   
   
5. I cannot see shares of the Saudi oil company Saudi Aramco traded in  الظهران in SAR from my provider only derivatives and bonds?
   Are stocks of Saudi Aramco generally not tradable, or where can you trade them?