British Cars. Their own "convention", probably copied by many others.
Our US vehicles with solid windscreen and electric wipers park right.
My US vehicles with vacuum wipers park...down. Left side to left, right side to right. That's the two with split windscreen. The one piece wind screen park right, but the pickup is and always has been LHD, so go figure.
Now....on my LBC....not a permag motor, field wound, with an offset cam...park right for RHD, left for LHD.
Mine is RHD, the wiper motor was a single speed (we think is was from a) Morris.
Find a proper motor (two of them to make one). Get it in, reconfigure wiring back to stock for two speed...then find you have to remove the park contact...flip it around and re-install...then, since they reverse when shut off to park the blade close to the cowl, you had to reverse the field to get it to run the right way and park low instead of high.
See how easy you have it?