I know the right thing to do would be to head out in the garage and taken them apart. But from the comfort of my computer does anyone know what width the brake shoes on my Zwitter should be? 30mm or is there a special Zwitter width?

Adam,

Hydraulic brakes up to chassis number 1-575 414 Front shoes part No 113 607 237 Rear shoes part number 113 609 237 both 30mm wide
Hydraulic brakes chassis number 1-575 415 to 1 673 410 Front shoes part number 113 607 237A Rear shoes part number 113 609 237A both 30mm

Cable brakes all years four shoes part number 111 605 237A and four shoes 111 605 238A all 30mm width

All 30mm width linings are interchangeable between cable & hydraulic brakes were part number 111 698 051(SP Set 311) up to chassis number 1 673 401 need 8 rivets per shoe part number N 13 634 1 (Rivet C4 x 7.5)

https://www.vintage-volkswagens-lavenham.co.uk/ 

Rod

Cheers Rod that's really helpful, and yes, I'm signed up for Lavenham, see you there.