Modern Vespa

Moving to a new storage space and found the slightest oil drip from the casings and then down towards the rear brake lever and then to the tyre. Literally only 6 drips but has anyone ever solved this slight leak with the best gaskets money can buy?

Yes, probably more than once. Not sure what it has to do w/ your six drops of oil though. More likely just a seal that's not new but still doing pretty good. I think what you are experiencing is more or less normal unless over just a couple of days. How long was it stored?

Stored since January.

If it has just been sitting, the leak has to be at or below the oil level which is way down low at the fill point.

Some of those fiber drain plug gaskets weep oil. I use 8x14mm copper washers now.

engine case using copper gasket instead of fibre gasket might work better.

"If doesn't drip it isn't a Vespa."
Not my quote

I have three bikes that drip a bit.
One has no carb filter and jetted on the rich side. Blow-back runs down to the floor (instead of being caught by a filter), like a few drips or so of oil (fuel evaporates before hitting the floor) over a week after riding.
Another has a few drips leak from idk where between the cases. PO rebuild with a paper gasket.
Another leaks from the clutch cover/lever. If you're seeing oil on the tire I'd suspect that. Definitely worth inspecting. Oil on the bottom of the lever is a tell.

Older cases can be sealed pretty damn well with VERY LITTLE sealant and a fiber Piaggio gasket.
There's also the rubberized aluminum Athena gasket.