I’m amazed that no one has put the chords for this up already. It’s a ukulele classic. I suppose it is more than a little over shadowed on A Night at the Opera with it being followed by Bohemian Rhapsody.
It’s no surprise that Brian May learnt the ukulele before the guitar. This performance is definitely not one of someone who is playing the ukulele like a guitar. He’s throwing in a lot of Formby moves. There are a few triplets and, in the solo, a bunch of sort-of-split-strokes.
I think he must be tuned up half a step to G#C#FA#. They certainly seem to be the more natural chord shapes. And they match the chord shapes he’s using in this clip of him discussing the track (but the uke is tuned way down).
For the strumming, he’s doing mainly down strums with a few triplets thrown in to liven things up.