Modern Vespa

My vespa occasionally leaked a drop of oil from under the transmission cover. Today I fitted a malossi multivar and noticed it was a bit greasy behind the transmission cover. I finished the job and thought I would ask here on the forum today what it could be.
After 15 minutes of riding with the new multivar (drives fatastically by the way), I found out that more oil is now leaking from the transmission cover. Not good!
I suspect it is coming from the oil pump which is behind the variator, has anyone solved this problem before?

1stly pics are worth a 1000 words.

Did you clean the area when it was open?

Take a pic directly after opening, ie before cleaning and after cleaning.

Usually it's the axle bearing seal behind the clutch that goes south. Try replacing that first - cheap and easy.
https://scooterpartsco.com/gts-300-hpe-drive-transmission-c-3637_4109_4113/final-drive-seal-83082r-p-9240.html

Just took the whole thing apart again, the leak is coming from the top of the oil pan. I already replaced the gasket there a few weeks ago, maybe I should tighten it more carefully.
The seal behind the vario doesn't look quite right either, it's not sitting straight in and the vario seems to be touching it.
I also noticed that the new malossi v-belt is touching.

Sounds like you have the same problem that users of Dr Pulley 'rollers' can have - the belt rides out so far that it can snatch at the top of the oil pan gasket and tear it. The cure is to place an extra 1mm thick washer between the inside of the out pulley and the centre bushing. This makes the belt ride slightly lower down in the variator, which enhances acceleration as a bonus.

My black SH had the crank seal replaced under warranty at 2,000 miles. Unclean pic would tell more.

You can see oil coming out of the oil seal at the crank. Are you the original owner, and have the cases ever been split, to the best of your knowledge?

while Jim's suggestion on the oil pan seal is spot on-- and that might be an issue as well (it's common), the main seal at the crank looks funny.

and not: ha ha funny; but funny: that's not good.