My wiper fell off! What are the spindles supposed to look like? (Pictures)

Series 2a. Was driving along the motorway the other day and my driver side wiper went AWOL! Was chucking it down too.
I pulled over and tried to bodge the passenger side wiper onto the drivers side but it didn't work too well.
This is what the spindles look like now. The driver side is flat on one side and the passenger is circular.



This is what the passenger side wiper looks like:


Are either of the spindles ok or do they need replaced? Or should I just buy some of these?
STC987 | Wiper splined adaptor drum

When I pulled over to sort the blades I undid my seatbelt and the buckle exploded! Was going to replace with inertia reels anyway.

Looks like you have a defender spindle on drivers side and Series on passenger.
Defender spindles can be seen here
landrover defender wiper spindle adapter | eBay

Just an update in case anyone reads this in future. I got the defender adapters and the drivers side fits fine. I will have to file down the passenger side spindle to give it a flat side but shouldn't be too hard.
Series wiper arms (the bits that the blades attach to) fit onto defender adapters.

my drivers side adaptor split when a lorry went past in main toad yesterday effectively stripping the thread in the aluminium-I fitted passenger side to get me home.

was gonna drill and retap my existing adaptor