Hi if you set out the front crank to tdc and look through the inspection hole on the gear box you will see a small plate with a few numbers in it that is your timing making I will try and get some pictures of my set up for you
I happen to deal with this very same problem, after a headgasket renewal job. While there is ample instructions to find on how to time a manual, with drawing of marks on flywheel, crankshaft pulley, camshaft pulley etc. it seems indeed impossible to find said instructions for timing of an automatic?
There are no clear signs on the flywheel at all. Anyway, o have another Golf MK2 automatic that runs fine, and I checked the settings on the flywheel when positioning cylinder 1 at TDC. It then seems that that there is a vague mark on the flywheel that lines approx up with the metal arrow in the inspection hole in the bell housing of the automatic transmission. It is not really a mark but a bump in the metal. There are actually two bumps, one is close to the end of the metal flange -this is not the one- the other is more towards the middle - this is the one. I have transferred this setting to my other car; it started at once and on first sight runs fine.
But this is still a very coarse setting so am not sure it will help you completely. I tried to fine tune it by using a timing stroboscope light but it is difficult to see whether you are spot on, 6 degrees before TDC (recommended for an 1.8 RP engine, at least for a manual?), as the "bump"is very course - left or right on the bump will make some degrees of difference. I could however see that the mark on the crankshaft pulley is pointing upwards using the timing stroboscope light, the same as it was in the reference car, so it is at least in the "right window", but again, I am still uncertain whether it is "spot on"
So, if anybody can direct us to drawings/instructions for precise timing of a Golf MK2 automatic, including marks on flywheel, very much appreciated!