And the winner is

[the civil one]

YOU.
I suspect you will be taking off the original indicators.
When you take off the inside bolt ,this holds the original indies on, this is the piece of kit you will be taking to your local engineering work shop to get a piece of hollow threaded bar on which to mount your new indicators to

 

[littleredrooster]

Whhooooooossssh!

Straight over me head, that one.

Did I miss summat?

 

[Panzer Patrol]

You and me both kidda, cmon Civil old bean whatcha on about ?
I'd be intrigued if I could spell it.

 

[snodog]

Changed my mind

ta civil one,
but it now sounds cheaper and easier to buy the Touratech minis.