The swivel apart of the connecting pipe is 3/8” BSP, to close one of the holes I use a lose swivel and a 9/16” bal.

beautiful bike.

It's BSF 5/8"x 20

Luis, are you missing some parts for the brake plate?

Hi Vincent,

I can help you with just the housing.

If you mean the rear chaincase then I can help you.

If you mean the rearchain cases then I have a set.

It’s not Square Four it’s for a 350 cc Ariel

I rode my 1925 Ariel W&P in the Irish National in 2016, they are wonderfull bikes to ride.

Great pics,thanks for sharing.