Have been to my 'local' modelshop and bought some copper wire. First I tackled the tarpaulin rail and then replaced the tie bars with copper wire. The plastic tie bars proved too flimsy:

While modelling I decided to change the build to Diagram O15. So I added a basic representations of the vacuum gear plus the missing DC III brake gear

Also added some much needed lead weight between the underframe scantlings (note to self: next time add weight before adding the solebars and assorted underframe details...)

Now it looks like this:

Now back to my modelling desk, painting the wagon in a grey undercoat

EDIT: model now painted in grey primer: