UK Tecumseh Lawn Mower

I have a UK bought Mountfield Empress 16 mower with a Tecumseh BVS R 153 engine with some Italian words printed in various places, like on the carb float.
There is a four position hand control, Choke, Fast/Hare, Slow/Tortoise, Stop. There is no primer pump.
It would only run on full choke, so I took apart the carb and found muck in it, cleaned out and cleaned the fuel tank. At first it wouldn’t run any better, so I tried changing the carb settings, which were disturbed anyway when I took off the carb. I don’t know if I made any difference, but suddenly it started to run OK.
I have not been able to find a manual for this engine, and from some old US Tec sites still in existence I cannot be sure if there is a different US number for this engine. One old US Tecumseh website doesn't list any BVS engine model.
Full number on the engine plate seems to be BVS R 153 ES E-41007B and another 6 digit number which is"3 8 or S"93"4?"1D
Although it seems to run OK, what I would like to know is how to adjust the carb settings properly.
Firstly the linkage and control mounting plate is adjustable relative to the carburettor body, as the screw holes in the plate are slotted to allow a quarter to half inch movement backwards and forward.
There are two throttle stops, one to limit the opening and one to limit the closure. I don’t see why the closure would be limited, surely the engine would stop if the throttle were fully closed only, or doesn’t it work like that?
There is another adjustment screw in the side of the carb body, which reminds me of an idle air bleed screw from my old Zenith auto carbs. It has some effect on running speed.
What is the correct way to adjust these and is there anything else I should know?

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