I dug around the forum and the internet and the first thing I found was this thread:
In this thread there is one of these units in it's original box with a serial number of: BMW 82 11 9 401 144
Through a google search his led me to this page which has the diagram with all of the parts listed:
Slid.lift. roof-cover/ceiling frame | BMW 7' E32 750iL M70 Japan
BMWFANS.INFO
Slid.lift. roof-cover/ceiling frame | BMW 7' E32 750iL M70 Japan
I included the breakout picture below, this breakout shows the individual part numbers of all of the mounting hardware:
23 Screw 72 60 1 852 660
24 Support 72 60 1 957 904
25 Nut 72 60 1 852 661
In searching for the support I found one source that allows me to add 2 of them to my cart, link to web page here:
BMW 735iL Support. Automatic, Manual - 72601957904 | Sytner Stevenage BMW, Stevenage Hertfordshire
WWW.SYTNERSTEVENAGEBMWPARTS.CO.UK
Support. Automatic, Manual. BMW 735iL. Genuine BMW Part - 72601957904 (72-60-1-957-904). Ships from Sytner Stevenage BMW, Stevenage Hertfordshire
Not sure if they actually have it but if I was interested I would go there and add 2 to my cart then try and check out, it is in the UK.
One last point, as you can see in the image I provided below this is not for a standard sunroof on a 2002 so I think you need to look at one more item, while also from the same link I got the part number from there is a picture of some BMW paperwork that shows 2 different lengths one of 21mm and one of 25mm.
My conclusion if it was me trying to mount this thing would be to roll the dice and try and order the 2 pieces from styner Steven link above and if they dont work to just get a strip of stainless steel and a vice and manufacture a couple of clips, it is literally a strip roughly 3/4 an inch wide and an inch and a half long with a hole and 2 bends. All you have to do is mock it up on your car and figure out what the distance between the top and bottom bend are and in the second picture below it gives 2 different lengths one of 21mm and one of 25mm so that is a good place to start.
Hopefully this gives you something to work with, you have the 2 mounts that came with the unit you can use to figure out what orientation they go in and then use a pencil or marker to mark where the tabs would need to be to clip in. If they end up being close to the 2 different lengths one of 21mm and one of 25mm then even better.
Hope that helps!
Good luck!
Post pictures of your end result that thing is going to look sweet!