Trying to save you a few dollars.
The brake system are made by "ATE" and are sized in inches, not metric. That means that the rubber sealing parts of the wheel cylinders are available from your local auto parts store. Sizes are 1" for the master & front cylinders and 7/8" for the rear cylinders.
Rather than replacing wheel cylinders, if needed, have them bored and sleeved with stainless steel liners. They should last forever.
Do you need new brake shoes or just linings? Unless you have warped or damaged brake shoes, I would have them re-lined by a good local brake shop.
Lastly, replace the brake hoses at the same time you do the rest of the brake work.
What do you mean by bonnet pin? Do you have a picture?