This is a very challenging part of the job - was for me anyway.
A great deal was about making the pan edge even (with a socket and a hammer or a brass bar and a hammer) to match the flat surface of the trans housing. Anytime the screws are torqued tight, the place on the pan edge near the screw hole gets dented upwards/raised.
If you have to remove the pan again, you may want to take a look at these potential dents/convexities (whatever the proper word is). Make sure you flatten them - tapping them down having a socket (I think 13mm) as support or a flat surface when turning the pan upside down and using a bar.
Make sure you use thin layer of the sealant, so that it does not get inside the trans when it is pushed out by pan as it is torqued.
Torgue - I think this is less than that (better check). You snag it with your thumb and two fingers holding just the head of the ratchet. You have washers there to prevent the screws from backing off. If you tighetend them too hard he first time, you might have made these dents/raised places again.
Start cross-pattern of snagging form the middle, four sides, then move one way by one screw at a time still using cross-pattern.
I was looking through the forum, but cannot find this torque for you. I found a mention of 1.3mkp for 280SL, which is around 12-13Nm, but I am not sure if this is correct. Kent is saying on the video "0.8Nm", but that cannot be correct probably. In any case - you probably do not have the wrench for this kind of torque. So just try to tighten it with "two fingers on the ratchet head". I did it twice, actually, worked both times.
Where I failed was the banjo fitting...